VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: TylerDurden on September 26, 2012, 08:56:41 am
-
Hi folks,
I pulled my engine from the '91 ECO and cleaned a huge load of grease/dirt off it. Cleaning revealed that block has three shiny freeze-plugs which I presume are not original. I am now concerned that the engine has clogged block passages or other issues. It boils over when running straight water and idles ~220F using 50/50 coolant.
When an engine freezes, does a bunch of scale and crud get loosened and collect in the block?
It would suck to install this engine in my daily-driver only to discover later that my block is literally stuffed and prone to overheat.
(https://lh6.googleusercontent.com/-dG6c0x3Q_9w/UGMdZQRBm7I/AAAAAAAAAvk/HTMNSq21GA0/s800/IMG_9116_med.jpg)
Backstory:
I purchased the car (cheap) as a non-starter. It sat for a year before I bought it and sat a year in my driveway. I purged the pump and the engine runs great from a bottle. Compression is ~425psi in all cylinders. The turbo spins, but is leaking plenty of oil into the downpipe. (The exhaust was broken off at the bottom of the downpipe.) The brake-lines are gone from rust, so I couldn't drive it around.
I flushed loads of grey silt out of the radiator.
I flushed out the engine and lines with a garden-hose and the water flows freely.
Running the engine with a new radiator, it boils over running straight water.
Running with 50/50 mix, the engine runs ~220F.
No gasses detected in the coolant.
Waterpump OK.
Thermostat OK.
Radiator fans OK.
Thoughts are appreciated.
-
When flushed the engine lines, how much crap came out of there? Did it have antifreeze in it or water?
-
IIRC, the engine had very little coolant in it when I got it. I topped it off with water before trying to start it.
I flushed the system, first by jamming a garden hose into the reservoir -> pump line and ran the outlet from the head to a bucket (engine running). It was pretty clear, with a few black greasy flecks. Then I flushed the heater lines both ways with the hose and flushed from the pump's heater return line, through the engine and out the upper rad hose & heater flange (bypass hose pinched-off) . The outflow was clear.
-
Do a chemical flush.
-
that all + I put fuel filter for clean.Best
-
that all + I put fuel filter for clean.Best
a fuel filter will do NOTHING to the running idle temps...
-
for sure the water pump is ok?
the impeller isnt spinning on the hub?
-
for sure the water pump is ok? the impeller isnt spinning on the hub?
I couldn't get it to move relative to the hub by sticking my finger in there and turning the hub, so unless the heat loosens it, I think it's ok... I will check again, now that the engine is out.
-
I couldn't get the impeller (cast) to budge, holding it with a prybar while trying to turn the hub by hand.
-
At idle, I'm assuming you run it for 15 minutes or so and then it boils over. Does the rad fan cut in before it boils over?
It's not a huge job to pull the coolant pump off. I think if it were my car that would be the first thing I would do and make sure the outlet to the engine was not severely blocked-and run a hose in there an make sure it was coming out the end of the head, or the top of the head (hose back to top of rad). If that's okay?? -Frost plugs next?
-
Ja, plain water boils over (cap open) before the fans kick on.
Additional info:The ball-reservoir walls are opaque with black residue, but the horizontal baffle inside is relatively clean, so I think there was floating oil or dissolved hose in the coolant at some point. The tstat housing (outlet) and radiator had a light grey residue inside. Maybe someone tried sodium silicate? I've never seen a system where that has been used (it *can* work as a hail-mary).
I tested the thermostat and it is apparently mismarked as a 160F - it is not fully open and extending enough to block the bypass until 190F. That will explain the difference in the temperatures compared to my '89.
Measured:
Pump's t-stat flange to bypass flange: 38mm
Tstat flange to bypass block-plate top (closed): 31mm
Tstat flange to bypass block-plate top (open): 42mm
The older thermostat seems to have the potential for more movement, but the new/mismarked tstat has enough extension to close the bypass at 190F.
What concerns me are the signs of trouble: freeze-plugs, silt in radiator and black tank. Everything may have been resolved, but the thought of a block with rust and scale sitting around the bottoms of the cylinders is nagging at me. (My experience with small-block Chevy V8s was that large debris would not flush out of the drain holes and the heads had to come off for a thorough cleaning.) OTOH, maybe all the silt and crap got captured by the radiator (there was plenty).
Consider me paranoid.
:-\
-
Sorry im just postin.didnt read all the other posts yet...
those 3 freeze plugs are 36mm....
grey nasty crap in the cooling system?
could you have had a blown head gasket before?getting oil in your water....
at my old shop,our little trick to get the oil out of a cooling system was to get some cascade and mix it in some hot water...throw it in the rad and run it.....ya may haveta do that a few times...flush it out with water tho,dont leave that stuff in there after its gettin cleaner..
ok ill go read more up above
Ok update...black crap in the catchtank def sounds like oil...im a little suspicious of your head gasket condition.....i know those freezeplugs are shiny,but i think they are orig.
head gaskets can blow 18 different ways...oil into coolant,coolant in oil...combustion into coolant,,combjstion into oil....keep countin theres more...
and the overheat thing? Im still suspicious of your headgasket,hate to say it
-
Ja, plain water boils over (cap open) before the fans kick on.
Have you tested the rad fan thermostat to make sure it's working right?
-
Thanks for your replies.
I will do a chemical flush after swapping into the other car.
I will repeat the combustion vapor test too.
The fan switch tests ok on both speeds.
Now that the engine is out, I'm much more likely to pull the water pump to look inside the hole; but just as much to lubricate the bolts in case I want to change the pump later without removing the IP. Gonna replace the IM shaft bearings as well.
If the freeze-plugs look original, then I am less apprehensive about prior freeze damage/debris. The main concern is a trashed block. If needed, I can do a head gasket in the car. (Fingers crossed)
-
Why is your cap open? It should be closed which raises the boiling point of the coolant.
-
Why is your cap open? It should be closed which raises the boiling point of the coolant.
I was testing the engine with water, cap on and off, then with coolant. It boiled with water and the cap on also. The only time it didn't boil, is with 50/50 coolant and the cap on.
My limited understanding, is that debris in the water jacket might result in hot-spots in the block.
The shiny new-looking freeze plugs made me wonder if a frozen block would result in debris and silt in the cooling passages.
-
Try a known good Tstat and verify there are no blockages. If it still boils over, I'd suspect blowñ head gasket or cracked head. You can test for combustion gas in cooling system with a block test kit. NAPA has it for around $45.
-
Thanks for your replies.
I will do a chemical flush after swapping into the other car.
I will repeat the combustion vapor test too.
The fan switch tests ok on both speeds.
Now that the engine is out, I'm much more likely to pull the water pump to look inside the hole; but just as much to lubricate the bolts in case I want to change the pump later without removing the IP. Gonna replace the IM shaft bearings as well.
If the freeze-plugs look original, then I am less apprehensive about prior freeze damage/debris. The main concern is a trashed block. If needed, I can do a head gasket in the car. (Fingers crossed)
get the problem fixed BEFORE you swap the engine maybe?!?!
-
get the problem fixed BEFORE you swap the engine maybe?!?!
Anybody could do it that way... j/k
A combustion-vapor test was negative. I ran the test until the tube melted from the steam, lol.
Well the engine is out, which is why I could see and ask if the freeze-plugs looked orig. Plus the donor car was non-driveable, so a real load test was not possible. It maintained pressure/temperature in the driveway, so maybe I'll roll the dice (unless somebody has an engine test-stand to loan).
-
Hey trav.didnt i text u a link to a cheaper combustion vapor tester from
summitracing.com
???i thougt it was around 25-29$
-
get the problem fixed BEFORE you swap the engine maybe?!?!
Anybody could do it that way... j/k
A combustion-vapor test was negative. I ran the test until the tube melted from the steam, lol.
Well the engine is out, which is why I could see and ask if the freeze-plugs looked orig. Plus the donor car was non-driveable, so a real load test was not possible. It maintained pressure/temperature in the driveway, so maybe I'll roll the dice (unless somebody has an engine test-stand to loan).
usually VW used brass plugs, didnt they?
i can remember if they used steel plugs or not, but im thinking not..
for the cost of 3 36.5mm soft plugs, i would pop them out and flush the block..
steel soft plugs are usually a buck or 2 a piece..
-
for the cost of 3 36.5mm soft plugs, i would pop them out and flush the block..
That's a damn fine idea... Will do.
-
Hey minor correction.the plugs are 36mm,not 36.5
-
Hey minor correction.the plugs are 36mm,not 36.5
Nope. They're actually 36.6mm. Just ask ETKA. 36mm probably still has enough interference to not fall out under cylinder pressure, but it's not right. I use 36.6mm ones.
-
We had every freeze plug under the sun when i worked at the engine shop.when i redid my tdi(ahu) i couldnt get the 36.5s to fit..the 36s worked fine tho...actually im not sure about the idi's tho.never had to change em in any of mine.whatever ya do,dont use those crappy rubber ones :(
measure 2x,buy once?
-
Hey minor correction.the plugs are 36mm,not 36.5
Nope. They're actually 36.6mm. Just ask ETKA. 36mm probably still has enough interference to not fall out under cylinder pressure, but it's not right. I use 36.6mm ones.
and since i can NOT EVER FIND 36.6mm plugs, i just use the 36.5mm plugs that i can BARELY get..
they are still a nice tight fit, ive got a few in my GTI, and one of my diesels..
every time i can find 36.5mm plugs around here, i buy all of them.. lol
yes, TECHNICALLY they ARE 36.6mm like Andrew said, but 36.5mm is the closest size i can cheaply get my hands on..
sure, i could prolly order the 36.6mm set, but they are gonna want $15 bucks.. atleast last time i checked, they wanted that much.. THEY WERENT EVEN BRASS!!
-
I knocked out the plugs and blasted the hose into the water-jacket through the openings, catching the outflow from the waterpump (sans t-stat) in a clean bucket.
There was very little silt, maybe a half-tablespoon... nothing compared to the dreck that came out of the radiator.
Thanks for the tips, I'll report back on the cooling situation after the swap is finished... sometime before spring, I hope.
-
http://www.autohausaz.com/search/product.aspx?sid=423qi5453prfuln515axl5qc&partnumber=036103113A
Dealer has them too.
-
So the flow into the reservoir is constantly flowing and increase with car revs? No spurting of air through that hose?
A family member overheated my jetta and it did that when I limped it home off the side of the road. Spurting gases constantly and in less than a mile pushed the water out and tried to overheat on the gage.
I would check the thermostat with a legit one and make sure its in proper range.
Another thing is if the system was being refilled, could it be an air pocket? I have only experienced this a couple times and the last time was just last week. I was doing the flush thing for multiple cycles with the car in the garage. One time I let it do a heat cycle and the fan operated as normal but then the gage started to move coupled with some rushing of hot overlow with reservoir(cap off the whole time)
The car has been driven daily since and there has been no temp fluctuations and no mixture/loss in the fresh coolant
-
I pulled the head on the 91. First thing I noticed was head bolt #9 had a bit more corrosion.
(https://lh4.googleusercontent.com/-r82DMq_fsxY/UKoZQF-5sgI/AAAAAAAAAx8/B1LHs6ZOrPE/s640/IMG_9144.JPG)
The gasket didn't have an obvious sign of breach and the block looks ok.
I'm still cleaning the head.
(https://lh3.googleusercontent.com/-GRc42bJzibk/UKoZP3dVGjI/AAAAAAAAAyA/pNdlakTMSV4/s640/IMG_9143.JPG)
The black grunge is stubborn, but eventually scrubs off with lots of solvent. The brown stuff is hard like varnish... What takes that off - sanding?
-
no first hand experience but I heard aircraft paint remover for the varnish. You Gonna runsone head studs Tyler? Is that the engine for your passat project?
-
Thanks for the tip on the stripper (lol).
I'l use TTY bolts, I got about thirty new lying here.
This one goes in my 86 Jetta. The Jetta's original will get rings and go into the B3.
I took a closer look at the head and gasket near the #9 bolt. A couple of deep scratches might be an issue?
(https://lh6.googleusercontent.com/-8I-yPFsNOio/UKp0edcWONI/AAAAAAAAAyc/dkIh0DPzrYA/s640/IMG_9145.JPG)
(https://lh5.googleusercontent.com/--FxoUMQd6ss/UKp0cxH7-YI/AAAAAAAAAyU/xst7jJ639Qg/s640/IMG_9149.JPG)
-
Thats what gasket sealer is for :)
-
My impression is that there gasket sealer was used. I wonder if it makes a difference right at the cylinder edge.
The engine would boil-over idling with straight water and the #9 bolt appears to have the evidence of water/rust. Interestingly, the corrosion easily brushes off the bolt, as if it were deposited there, rather than the bolt itself being corroded. There was no evidence of water in the oil, or oil in the water.
-
Thanks for the tip on the stripper (lol).
I'l use TTY bolts, I got about thirty new lying here.
This one goes in my 86 Jetta. The Jetta's original will get rings and go into the B3.
I took a closer look at the head and gasket near the #9 bolt. A couple of deep scratches might be an issue?
(https://lh6.googleusercontent.com/-8I-yPFsNOio/UKp0edcWONI/AAAAAAAAAyc/dkIh0DPzrYA/s640/IMG_9145.JPG)
(https://lh5.googleusercontent.com/--FxoUMQd6ss/UKp0cxH7-YI/AAAAAAAAAyU/xst7jJ639Qg/s640/IMG_9149.JPG)
the rather large cracks in the precups would scare me off this head. I would guess your head surface maybe to blame, but there is not much there to go off of.
-
Ja that kinda stuff makes me nervous, having read the horror stories. But, the other precups look ok. I prolly ought stake them for safety's sake.
Paint stripper didn't make a difference on the gasket varnish (or whatever that stuff is), it's harder than the really crusty soot, which is like bakelite. I can see why some shops sand the heads, but I didn't want to pull the cam.
With winter on the doorstep, I'm shooting for the sensible shortcuts, but not the one's I'll pay for dearly in the long run.
-
Pardon me if I'm wrong....but, three pages deep in worrying about the head and no mention of putting a damned straight-edge to it? THAT'S where I start!
Initially, you stated that you had 425 psi across the board. I have yet to open up an older engine and get such an even distribution....especially one with oil in the coolant ::).
Things here don't add up.
Could be wrong...been wrong before.......
-
10-4.
Still getting the crud off... it's thick.
-
I always lightly sand the face of heads utilizing a precision ground block with sandpaper...400, 500, 600 grit (if I have not had it ground or machined). You simply have to keep your pressure the same and make an honest attempt to make passes all over the head (evenly...same amount). This cleans them up very well and will smoothen out those little dents you have (to a certain extent).
I put an '84 Jetta engine together last week with some little dents and the engine runs extremely well. But, I knew this head was flat by employing a straight edge. I also carefully inspected the cam caps and used plastigage.
The engine I worked on also had two head bolts with the identical debris. We used a bottoming tap and lots of air and brake clean to clean out the threads prior to assembly. Attention to detail pays dividends.
-
I'm hopeful that the head is straight, since the compression numbers were good. I will check when I get the garbage off it.
Another post somewhere said a palm-sander with 800 paper and wd40 for lube can get the gasket varnish off... Y/N?
If the head is toast, can a 1.9 head be used? (AIUI, new 1.6 heads are N/A)
-
I'm hopeful that the head is straight, since the compression numbers were good. I will check when I get the garbage off it.
Another post somewhere said a palm-sander with 800 paper and wd40 for lube can get the gasket varnish off... Y/N?
If the head is toast, can a 1.9 head be used? (AIUI, new 1.6 heads are N/A)
I would not use the palm sander since it will not know high spots from low spots. Use a flat plate the width and length of the head, double sided tape to glue 400 grit wet/ dry paper and use WD-40 as a lube cleaner. Flat plate can come from 1/2" plate glass or plexiglass.
-
10-4.
Thanks for the tips folks.
Many more Qs to follow, I'm sure of that.
-
I can see why some shops sand the heads, but I didn't want to pull the cam.
It's 10 nuts, and only 4 of them matter what order you take them off in. Easy Peasy.
-
Shortcuts rarely turn out to be.
-
Ja. I was hoping for a quick engine swap and then reality came calling, lol. Stupid not to do the stuff that's easy when the engine is out.
-
Pulled the camshaft off and started sanding the head surface.
The small gouges look better, but some others are a small concern. I think copper sealant should resolve those issues.
(https://lh5.googleusercontent.com/-pvMQckHuf8E/UKwjYpaan5I/AAAAAAAAAys/9ygQ7Z_DGaQ/s800/IMG_9150.JPG)
(https://lh3.googleusercontent.com/-9XGQMPA9k0E/UKwjm-UbdmI/AAAAAAAAAy4/vcnZpLcV4BM/s640/IMG_9153.JPG)
(https://lh5.googleusercontent.com/-n2twGYrswW4/UKwjmi6mZoI/AAAAAAAAAy0/indUiQDzERk/s640/IMG_9154.JPG)
This one is odd: it sems to have been partially milled off-axis...
(https://lh3.googleusercontent.com/-FeCil1qAytk/UKwkDZjpLZI/AAAAAAAAAzI/MW_dXLGx0Ig/s640/IMG_9155.JPG)
I got a 7x24 tempered glass shelf at the store and taped the 600grit to it. I lubed generously with wd40 and slid the head back and forth longitudinally.
(https://lh4.googleusercontent.com/-j9levMMKSiY/UKwkDHS_pJI/AAAAAAAAAzE/Agbw8NmSBuI/s640/IMG_9157.JPG)
I'm not sure I want to sand any further... The straight-edge currently shows no gap end-to-end and corner-to-corner, but the openings of the precups seem about .001" proud. If I keep sanding, I'm concerned that the precups, which are harder, will let me rock the head back and forth on them and create a rise, since there is no way for me to force the head to maintain the same plane as the glass.
-
It did clean up. I would check for gap between the cylinders as well. I currently have one head disassembled with about 3.5 thousandths between #3 and #4. Not sure what I will do with THAT.
Personally, I get the feeling this engine has been manipulated to some fashion before. I don't think those soft plugs in the block are the originals...not even. All of these valves look like they match. I can't remember if the new TRW's have that same small dent or not.
Wonder how much wobble the valves/guides have? I would recommend stem seals if you have access to a valve compressor. The precups generally always protrude a bit. Not sure why one of them sits in there different.
Here is a question I have regarding peening a head around the precups: if a guy peens these....does THAT totally rule out sending the head back for a core to a rebuilder? In other words, do most exchange-rebuilders accept peened-precuped heads as cores.....or do you lose your head and have to fork over the core charge? Just curious.
-
Ja, I have seen quite a few pix online, and none had the machining marks I see on the head, precups and the block.
(https://lh5.googleusercontent.com/-6zwe3eoWbCY/UKxQwLZA9dI/AAAAAAAAAzg/vNbHuvGNJ0o/s640/IMG_9142.JPG)
(This is just after a very light scrape yesterday with a new carbide blade. The peaks are faint, but enhanced by the gasket residue.)
The PO said he was a wrench at FedEx... parked the VW after it dropped the exhaust and drove his Jeep thereafter. Hmmmm.
-
I had corrosion pits in the head around the coolant flanges and near the oil drain hole where it would seep coolant (92 Eco). I cleaned the pits down to bare metal, filled with epoxy then wet sand, repeat till smooth. Fixed the leaks.
Another way would have been to get a shop to tig weld aluminum to fill the pits and sand it flat. I didn't want to look for a shop to do that and end up with longer down time and possible complication and wanted to try the epoxy so that's my story.
-
Ja, I have seen quite a few pix online, and none had the machining marks I see on the head, precups and the block.
(https://lh5.googleusercontent.com/-6zwe3eoWbCY/UKxQwLZA9dI/AAAAAAAAAzg/vNbHuvGNJ0o/s640/IMG_9142.JPG)
(This is just after a very light scrape yesterday with a new carbide blade. The peaks are faint, but enhanced by the gasket residue.)
Use your plate glass /600 paper on the block also.
The PO said he was a wrench at FedEx... parked the VW after it dropped the exhaust and drove his Jeep thereafter. Hmmmm.