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General Information => Troubleshooting => Topic started by: aidan on March 18, 2007, 11:32:31 am
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The temperature on my GTD goes to 3/4 very quickly. It never goes above or come back down, and it doesn't change regardless of my speed, i.e I can be sat in traffic at that temperature, I can be on the motorway at 60 at that temperature, and I can be thrashing it around 30-50 up hills etc at that temperature.
I got it to that temperature and let it idle, the fan wasn't coming on.
I previously had a problem where the car wouldn't warm up at all past the lowest stop on the gauge, I would have no heat in the car. Then it suddenly went to half way and stayed there, I would have plenty of heat in the car.
There is now no heat through the heater in the car.
There is pressure in the header tank, presumably from this overheating.
Does this all point to faulty thermostat?
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it could actually be a faulty expansion tank cap. your best bet would be to try and bleed the system by running it without the expansion tank cap on. use a thermometer to see what the temp is. it should drop around 86.5C or so.
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Nine times out of ten funny temperature behaviour starts at the thermostat.. the Bentley has the proceedure for testing... if you replace it be sure to test the new one... they have a long and honoured history of being bad from the factory... doesn't seem to matter which brand.
Second guess is the impeller spinning on the water pump shaft... I'm guessing your's is a mid-80s TD so at least you don't have the plastic impeller of the early TDIs, but spinning is not uncommon.
Third guess is some kind of blockage, collapsed hose, nasty air bubble, etc. When you check/change the thermostat or look at the pump you'll have the opportunity to drain the coolant and give the system a good flush... any funny sludge in the old coolant ?
Fourth guess is the expansion tank cap as previously mentioned... I've read about a recall on the black ones and blue replacements... mine is black and I've never had a problem but if they malfunction weird pressure things can happen which turn into weird temperature things.
Good luck.. tell us what you find out !!!
Vince
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It had a new blue cap last week.
Its a 1991 SB GTD. I bought it around 3500 miles ago with a bust front engine/gearbox mount, the whole thing tilted forward and the alternator cut the lower radiator hose.
I refilled it then, purely through the expansion tank.
The lower hose came off again unfortunately a few weeks ago, emptying all the coolant again.
It overheated a little last week, when opening the cap at least 2 litres of coolant came out. Running the cap a little loose so the pressure doesn't get high has probably lost a couple more litres.
Basically its had about 3 cycles of coolant in 3500 miles if you know what I mean.
The coolant is fine, no sludge. There is no coolant in the oil. The oil level has not dropped in the slightest since I had it (did oil change when I got it)
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Fifth guess (we're really in the weeds now!)... head gasket leak, causing compression to pressurize your cooling system. Did the lower rad hose fall off or explode off ??
Classically the test for this is to start the engine from dead cold... let it run for a minute or so, stop the engine, and then unscrew the expansion tank cap. If it hisses it's probably being pressurized from a leaky head gasket (too soon for heat to have caused pressurization). A proper compression leakdown test can done to confirm.
Any idea how many miles on the head and gasket ?? Did it overheat the first time enough to warp the head?
Vince
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The hose fell off, it seems the lower outlet of the rad was slightly damaged when the alternator dropped.
I started it earlier and held my hand over the top of the tank, couldn't really feel any pressure building up. Took the cap off shortly after starting it the other day and no hissing.
I will go and try it again now.
When it was running cold though, I could take the cap off in the morning and it would hiss and spit out a bit of coolant.
I believe the head and gasket are original, so around 146,000 miles and 16 years.
When it overheated the first time I would say it could have warped the head, as it was steaming from the engine bay, and there was constant faint white smoke from the exhaust.
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Ok, just started it for a minute or so,
There is pressure build up - when the cap is released its kind of a burp, definitely not a hiss? Probably the same thing I guess
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White smoke in the exhaust, hissing/burping from the coolant tank when cold... doesn't sound good for the head gasket.
Quickest thing now would probably be to check compression... or ideally do a leak-down test so that if there really is a leak you'll pinpoint it exactly.
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hmm yea those problems suck. at idle my temp is perfect. the fan even comes on! but when i'm driving down the highway the temp gauge will creep right up and fan does not kick in (so the hot coolant is not getting to the rad...)
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Sorry the white smoke was only that at that first overheat, doesn't do it now.
I think the head gasket is the likely culprit, oh well its only a work beater i'll see how it goes.
More worryingly I noticed the clutch release bearing rattling last night, very loud, and today when coasting along around 1000rpm in 4th a very strange rumbling sound from the gearbox, went when the clutch was depressed. I'm more worried about the gearbox letting go first to be honest.
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hmmm its not a good idea to be driving 1000 rpm in such a high gear... think of all the stress the crank is under! I find that if i am going downhill, or on a level ground, 1000 rpm is fine. it's whenever i'm going up an incline that the engine starts to vibrate because it doesn't like it. saves fuel yes, but remember to downshift when the engine is getting stressed.
gotta love diesels though! gasser's get fouled injectors if ran at low rpm's... we can run low rpm's all day long 365 :)
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It was just slowing down, and basically pulling itself along then, I wasn't touching the accelerator.
PS Jtanguay see if this seller has anything that interests you http://search.ebay.co.uk/search/search.dll?sofocus=bs&sbrftog=1&catref=C6&from=R10&satitle=iveco+diesel+pump&sacat=-1%26catref%3DC6&sargn=-1%26saslc%3D3&sadis=200&fpos=B987XT&ga10244=10425&ftrt=1&ftrv=1&saprclo=&saprchi=&fsop=1%26fsoo%3D1&coaction=compare&copagenum=1&coentrypage=search
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hmmm those iveco pumps are IDI right? still not too bad of a price ;) :wink:
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it could actually be a faulty expansion tank cap. your best bet would be to try and bleed the system by running it without the expansion tank cap on.
I think this is great advice...
The fact that you have NO HEAT points to an air lock somewhere in the system. I find this sonetimes happens when you change the main hoses, or splice into the system.
In fact, I just battled the exact same symptoms in my Samurai last week. I had spliced in long coolant lines for my SVO tank, and didn't bother to prime them with coolant. Lo and behold, I ended up with an air lock. Friggin thing would overheat without even having the thermostat open, and no heat to the cabin. There wasn't proper circulation.
Running with teh expanion tank resevoir opened was sufficient to "burp" the system, but sometimes I find I have to undo the upper rad hose from the rad, and fill the block from it.
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hmm yea those problems suck. at idle my temp is perfect. the fan even comes on! but when i'm driving down the highway the temp gauge will creep right up and fan does not kick in (so the hot coolant is not getting to the rad...)
That's a classic symptom of a slipping impeller. At lower rpms it's likely moving enough coolant that your fan comes on. At higher rpms it slips enough that it stops moving coolant, the fan doesn't come on because the coolant in the rad is below your sensor temperature. We had a few Cummins engines at work with this problem right from the factory.
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hmm yea those problems suck. at idle my temp is perfect. the fan even comes on! but when i'm driving down the highway the temp gauge will creep right up and fan does not kick in (so the hot coolant is not getting to the rad...)
That's a classic symptom of a slipping impeller. At lower rpms it's likely moving enough coolant that your fan comes on. At higher rpms it slips enough that it stops moving coolant, the fan doesn't come on because the coolant in the rad is below your sensor temperature. We had a few Cummins engines at work with this problem right from the factory.
right from the factory??? damn... I was hoping this wouldn't be my problem, but if it is i'd rather know about it. so now, the water pump is slipping, can i not just spray the belt with some belt dressing and see if that fixes it temporarily? if it does then all I need is a new belt??? I do have a new belt to throw on... or is it something internally that is slipping??
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Jtanguay - they are DI pumps, didn't notice at first but only the first one is from a turbo DI. They are 3 litre engines I think, 11mm pumps if they are the same as before.
I'm leaving the expansion cap quite loose so the pressure can escape, have done for around 100 miles or so so i'm thinking air would have cleared now? Especially as i'm adding around 1litre a day back thats lost through steam and spillages
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DI pumps for that little cash? damn! good price. I'm thinking that my water pump pulley is slipping at high rpm. 3k rpm on the highway is cruising at around 100km/h because my gearing sucks.
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oh yea aidan have you tried running a chemical flush through the rad system? I have done that, and it seems to have helped. i have no problems getting heat through the vents :) VERY hot air comes through when my temp is climbing. enough to burn my hand or cook meat like a convection oven! :lol:
if you're not getting hot air coming through your vents, then get your car to operating temp and feel the coolant lines going to the heater core, if they are both lukewarm then its plugged. if its hot then its probably a problem with the vent doors.
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right from the factory??? damn... I was hoping this wouldn't be my problem, but if it is i'd rather know about it. so now, the water pump is slipping, can i not just spray the belt with some belt dressing and see if that fixes it temporarily? if it does then all I need is a new belt??? I do have a new belt to throw on... or is it something internally that is slipping??
Actually where we were having the problem was internally, not the belt on the pulley. The impeller blade just went over the pump shaft, and the end of the shaft was then peened to hold the blade. Once we took the pumps off, you could hold the pulley, and turn the impeller without turning the shaft. The pulley was working fine, and a lower rpms the friction was enough to create some flow, but once the rpms went up and the impeller started to slip it was game over.
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right from the factory??? damn... I was hoping this wouldn't be my problem, but if it is i'd rather know about it. so now, the water pump is slipping, can i not just spray the belt with some belt dressing and see if that fixes it temporarily? if it does then all I need is a new belt??? I do have a new belt to throw on... or is it something internally that is slipping??
Actually where we were having the problem was internally, not the belt on the pulley. The impeller blade just went over the pump shaft, and the end of the shaft was then peened to hold the blade. Once we took the pumps off, you could hold the pulley, and turn the impeller without turning the shaft. The pulley was working fine, and a lower rpms the friction was enough to create some flow, but once the rpms went up and the impeller started to slip it was game over.
is there many reported cases with vw's??? man I really don't want to change the WP... :(
http://parts.autopartsonlinecanada.com/parts/apocanada/quote.jsp?year=1991&product=G3000-170730&application=000610161&part=Water%20Pump&category=G
on that site its showing me 3 different style WP's... is going with the cheapest one okay??? or is the OEM one my best bet?
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I could be wrong but I think the ones from Canadian tire come with a lifetime warranty and are $50
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lifetime warranty... i'm down for that ! 8)
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Before you panic to replace that pump, open the thermostat housing, removing the T stat. Now you can see the WP impeller. Hold the pulley and try to turn the impeller. This simple check should satisfy all your questions about the coolant pump impeller integrity. My experience has shown that the pump is not the problem. Overheating is caused by all sorts of issues but with the average age of the diesels getting older don't overlook simple things like the amount of wear in the engine. Typical problem areas are rings and valve guides supplying significant amounts of fuel in the guise of lubricating oil. Fuel equals heat. Solution is simple. Rebuild the engine.
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but doug the issue is that my rad fan isn't even kicking on... it does kick on at idle though. mainly because the hot coolant isn't even making it to the rad.
i can only hope that there isn't permanent damage to the engine from this. (i always make sure to drive carefully and limp home if the temps rise too high)
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your rad isn't clogged in any way?
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JT, I went through the same thing as you. I carefully bled the system, changed T stat for an OEM, put a new reservoir cap on (system pressurising), checked WP for impeller slippage, installed a new alternator/WP belt, removed the rad and flushed with a garden hose, changed the lower rad hose and bypass piece, double checked timing belt pump/crank settings all to no avail. When I finally decided to do some engine work after a long journey that confirmed excessive oil consumption and also saw the engine temperatures get high considering that it was -25C (7litres/1500 Km), I was pleasantly surprised to find that the temperature guage seemed to settle down at a steady 5/8 position with little variation and the fan never seems to operate (maybe I should check the relay sensor in the rad?) The car does not get hot at idle to the point of needing the fan which it did before. Oil consumption has continued to improve as I assume that the rings are conforming to the slight out of concentricity of the bores (rings only replaced). The oil consumption is now below a litre/2000 Km. What do you think about my hypothesis?
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well funny thing is... i flushed everything but the rad :oops: because i flushed without the thermostat.
ever since i got the new thermostat the car has been overheating. (only say 100C max which isn't so bad.. at that point i let off the pedal and watch it go down...)
my car will hold perfect temperature at idle. that's what really gets me.. and my car doesn't burn oil either... mainly because its 5w50 synthetic oil. well okay the past 2000km it probably lost about 1 litre, but I'm still working out some issues with the dipstick, as in maybe i put too much oil to begin with?? :roll: :oops:
but if the rad was clogged, then at idle would the coolant still flow through it enough to kick on the thermoswitch and turn the fan on???
I'm going to try the WP route... there's no telling when the PO changed it.. I'd even assume it's the original! approx 386'000km...
Oh yea I also got rebuild injectors from smog that andy2 helped me install. that seems to have lowered the temperature as well. not much but it is helping.
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So have you removed the Tstat? If you take that out the water pump impeller is visible up in the casting hole. Try spinning it with your finger or a piece of dowelling while holding the pulley. If it doesn't slip I would assume that it is still good. Mine was metal but some are plastic. Maybe it is time to replace the rad but I would flush the rad with a high volume of water first.
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well i'm going to be buying a WP from ctire as well as an alternator pulley... i figure that i'll check the impeller on the WP first and if it spins i will definitely change it... if its nice and solid with the pulley then I will consider biting the bullet to see if it works...
i have full confidence that its either the expansion cap or the WP.
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If you haven't replaced the cap, why not start there? They are only about 6 bucks and way easier than a pump!
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well i'm going to be changing pretty much everything just to be sure... $40 for the WP isnt so bad.. changing it is another story!
so ctire doesn't sell the pulley for the alt... i'll probably just bite the bullet and buy one online somewhere, or maybe just consult etka.
and the WP... they've got around 4 different types... 40mm 30mm different bolt patterns... very weird!!! hmmmm
bah screw it i'm going to owasco and getting them to order up all the pieces i need... probably going to cost me though....! $40 for a pulley is a bit ridiculous... but it will last
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the 8 or 9 bolt doesn't make a difference if you are changing the whole unit, even if you aren't changing the housing I've interchanged the 2 without problems.
30mm or 40mm is just the size of the hub that the pulley bolts to. It might even come with a new pulley but I forget now.
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the 8 or 9 bolt doesn't make a difference if you are changing the whole unit, even if you aren't changing the housing I've interchanged the 2 without problems.
30mm or 40mm is just the size of the hub that the pulley bolts to. It might even come with a new pulley but I forget now.
yea i got the guy to check.. didn't come with the pulley :(
i'm wondering if it could be the pulley itself... the alternator pulley is soo smooth and shiney! the belt has been 'buffing' it real nice :roll: i may try to use the soap trick to indicate if the belt is slipping on the WP, which i doubt, but is always a possibility!
just makes no sense to me... at idle the temp comes right back down. on the highway i can drive 100km/h with the heater on max and the temp still climbs too high for my liking... for back and forth to work its great though!
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any luck jt?
i'm experiencing a similar problem. car gets hot, within about 1 tick of red. but, the lower rad hose stays cold and the fan never comes on.
i've replaced:
- expansion cap
- all hoses
- thermostat
- waterpump & v-belt
- rad
at this point i'm thinking i either have a really bad airlock somewhere (although i've bled the system properly and filled through the upper rad hose), or that i got a bad thermostat from the dealer. i didn't test it before i installed it. :o
pics for fun:
(http://www.voiddesign.com/pic/DSC00074.JPG)
(http://www.voiddesign.com/pic/DSC00078.JPG)
(http://www.voiddesign.com/pic/DSC00080.JPG)
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no luck as of yet... i've been considering an air lock myself actually.
i see you've re-used the housing.
man that looks like it's easy to take the WP off! im jealous! :lol:
the guy at vw dealership says that pulley's don't wear... its mechanical? come on... anything with anything rubbing against it will wear over time especially 400'000km and mean driving :twisted:.
in your setup it almost looks like the alternator tension is in direct relation to the water pump tension. and that there's only about 1/4 of belt spinning the pump (damn i hate v belts with a passion) my old '86 TD had the same setup... nice and simple!
maybe play around with your tension. i've also tried things like belt dressing etc... nothing really works.
one thing i should probably take into account was how i bled my system.. i ran the car from cold to operating temp with coolant cap off. then put it back on with a hot system (not a good idea, for those of you who don't know, this creates a vacuum)
i've just thought of that scenario... what i'm going to do tomorrow is run the car up to operating temp, give it some good shots once warm, then let the engine cool with cap off and put it back on. if that doesnt fix it.. i dunno!
i'm currently running some tow cool stuff from c-tire as a precaution too.. so when i say that my temps are creeping up to 3/4 mark, without that tow cool stuff i'd say that my car would be another tick higher. i'm surprised at how well of a job it does at controlling temp. must be a good conductor.
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man that looks like it's easy to take the WP off! im jealous! :lol:
the guy at vw dealership says that pulley's don't wear... its mechanical? come on... anything with anything rubbing against it will wear over time especially 400'000km and mean driving :twisted:.
in your setup it almost looks like the alternator tension is in direct relation to the water pump tension. and that there's only about 1/4 of belt spinning the pump (damn i hate v belts with a passion) my old '86 TD had the same setup... nice and simple!
maybe play around with your tension. i've also tried things like belt dressing etc... nothing really works.
jtanguay,
The pulley is just formed piece of metal that can be removed from the nose of the WP shaft. If it retains its shape and appears to be spinning true, I wouldn't feel the need to replace it.
I think the v-belt has enough tension in my car, I have it at about 2mm deflection and the contact angle is sufficient. From what I can tell, it moves quickly at idle without slippage.
I took some more pictures when I changed the waterpump, they are here:
http://www.vwdiesel.net/phpBB/viewtopic.php?p=56200#56200
The waterpump job was not bad at all. The 8 bolts holding the WP halves together came out without issue.
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thanks for the info! i'm either going to try and change just the WP in the car, or i'll finish getting the m-TDI ready! got the m-TDI pump, just need alternator & a/c compressor for the serp belt.
i'm also going to be cleaning up the TDI.. all that soot on the intake can't be good!!! the buildup is horrible.
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cool. waterpump should only take a couple hours. the pump is about $40 through altrom or the like. not sure what your intentions are with the old (current) motor but it will be worth a bit if it is known to be a good healthy runner.
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cool. waterpump should only take a couple hours. the pump is about $40 through altrom or the like. not sure what your intentions are with the old (current) motor but it will be worth a bit if it is known to be a good healthy runner.
the turbo is great! i bring it up to 20 psi on occasion... doesn't take long at all to get up there! and the wastegate works perfectly too, but its disabled atm. (it was overheating even before the wg was disabled)
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Been interesting to read what has transpired here - I have just finished living it! It all started when just after purchase of the car three months ago, I elected to perform my usual changing out of all the fluids - engine, tranny, brakes, coolant.
Since I was changing the coolant, felt it was perfect timing to change out the lower rad hose and the thermostat. Shortly after this my temp gauge started climbing.
Temp running at 7/8 consistently and no fan coming on. The only thing I did not change was the rad termoswitch & the WP. Purchased a WP and elected to hold off until I exhausted a couple of options. Have not got around to the termoswitch - yet.
I cannot stress how much troubleshooting occured. Belts, changing thermostat again, second flush of the system, vacuum purge of air (vacuum lift I believe it is called), expansion tank cap, etc, etc.
The answer - OVERFILLING the expansion tank. The expansion tank is no longer transparent and though I could see the MIN mark, I could not see the MAX line or its level relative to it.
Long story short, too much coolant resulting in too much pressure, resulting in 7/8 temperature at all times!
Reduced the coolant level, and all is good - stable at the half way point.
Next job, get the rad termoswitch in place.
What is your rooking mistake the rest of us can learn from?
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well i got away with a bad thermostat... the dealer one wasn't opening till 100C... so much for an '87C t-stat! :roll: