VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: mtnsammy on January 13, 2008, 04:17:23 pm
-
I am once again lost. Here are the symptoms and what I have done.
White or gray smoke from fire up to running warm.
Full throttle = more smoke but if I turn up power screw it definitely adds black smoke to the exhaust.
Motor will not start unless I preheat block.
Cold start has little to no effect after motor is running.
Cracking one injector at a time has no change but good spray from joint.
Bypassing filter shows no change, and disconnecting fuel line shows good flow from tank pump.
I have checked and rechecked the timing with no change. No adjustment needed each time I check for skipped belt or wrong pump setting. I am aiming for 99 on the pump.
The smoke is very thick but has little to no odor different from the normal exhaust. There is no sign of water in oil or exhaust gas in water. No water losses either. If anything motor is still running too cold. The temps are in the 40's here. The injectors were changed with glow plugs 500 miles ago.
Any help is appreciated as well as recommendations of a great diesel shop near Victorville California. Many out here charge High dollar and give bad service. They seem not to know what they are doing and just change everything out until it runs. The IP out here averages at $750 and it is the first thing they want to change. I do not think it would go belly up over night.
-
compression test?
-
385... before the rebuild I was closer to 500 but they said that was too high. It has been steady at 385 since then.
If someoe can tell mehow to insert pics I can post a couple small photos[/img]
-
Umm did you just say that you were told that 500 psi is too high and that after the rebuild the compression is at 385?/????
-
Never agreed with them but it has been smoking more and more since the rebuild. I plan to pull the head and check to see what gasket they used as soon as it runs smooth. The compression is steady and the powere was OK at first.
I read anothers thread and I think I may have an air leak at the back of the IP from setting the timing so many times. I never thought of changing the gasket for the bolt. I know there are no air leaks up to the IP so maybe the bolt is leaking air into the IP??
Factory compression is 415-500psi. I know what it should be but I do not have any quality machine shops nearby. It ran and I didn't have time to mess with it. I'll buy a new gasket for the IP and repost tomorrow.
-
Never agreed with them but it has been smoking more and more since the rebuild. I plan to pull the head and check to see what gasket they used as soon as it runs smooth.
You should be able to see the "notches" or holes in the gasket without removing it... it's on a tab that sits outside the engine to the left of the main oil gallery.
Don't have a picture handy, but if you search around a bit you should find one.
Any idea what gasket you have before the rebuild ?
-
3 notch on first assembly. The tab has been cut off or modified. I tried to see what they used right after I found the compression was 385.
The new gasket did not change anything. THe smoke is through out the powere band naturally worse at high RPM with the extra air flow. There is no difference with any single injector so I kinda doubt it is the injectors. I just would hate to spend $500 on a rebuilt IP and still have the same problem. The shop wants to rebuild the IP (500) replace injectors (300 ) and time the motor too (150 labor ) That 950 will give me the custom axle parts I wanted on my next upgrade. I wish I could find a shop to test run the IP for me without the high shop costs. Even if I deliver it they want $100 just to flow check it.
-
Is your engine heating up properly?
385 is low but once it warms up it should not be smoking
-
Is your engine heating up properly?
385 is low but once it warms up it should not be smoking
Indeed. It sounds like your car is not warming up properly. Is your T-stat stuck open or missing altogether? White/gray/bluish smoke on startup is normal, but it should clear up after about 1-3 minutes of running
If you have a Rabbit (older than 1984), and your IP is timed properly (i.e. at 1.00 mm of static timing), then the cold start lever will do absolutely nothing at all. You'll only really notice a difference if the timing is slightly (or greatly) retarded.
Did you set your static IP timing with the lever all the way in? If the lever is out, it affects the timing. From the symptoms you describe, it sounds like you did the IP adjustment properly.
Once the car warms up, that white smoke should dissappear. The fuel screw adjustment makes black smoke, as there is more unburned fuel. So, the fuel screw setting is likely fine.
I'd check the t-stat. As burn-your-money notes, 385 is a bit low for compression (near the wear limit), and starting may be a bit harder, but that should not create plumes of smoke that last longer than about 1-2 min. My old rabbit had about the same compression. While it was a bit hard to start in cold weather, it always started and did put out a puff of white/blue smoke.
There is one thing that catches my eye in your descripton: the fact that it won't start without preheat. By preheat, you mean plugging it in with a block heater, or preheating with the glow plugs? If you have to use a block heater, then there is definitely something wrong with your glow system. Check the fuse, check to see that the connections are clean and tight, and check for power at the glow plug buss. The glow plug dash light will come on, even if there is no power going to the buss/fuse/plugs. If by preheat, you mean 'glow the plugs', then that is normal.
Another cause of white smoke is buring oil. If your valve seals are bad, you'll see white smoke on start-up and when accelerating after a stop. If you have bad rings, you'll see white smoke at all times.
Either way, the compression is a bit low, but probably not the cause of the problem. The only internal problem I could forsee is bad oil-scraper rings or valve seals.
Let us know.
-
They want 300 to redue the injectors :shock: That is straight up robbery.
Sounds like you are getting dry reamed.
-
THe block heater is used to preheat. It is 30-40 outside now and even my ugly Ford needs some pre-heat.
I am going to redo the compression check and try it with a spoonful of oil. The motor is a 1.6TD from a Jetta installed in a Samurai. I must admit my luck has been far from good so far with this motor but when it runs nothing beats it.
Glow plugs tested at 35 ohms so I assume they are good.
Motor ran great at 385 compression for a few months until the smoking started. At first it was just a little but it gets more and more as time goes by.
Again I wish there was a way to home check the flow test on an IP. If anyone has a home bench setup I am a great fabricator. All I need are the IP specs and a good picture. This week I am going to try the local COllege to see if a kid needs a project IP for the shop. I thought I saw a bench from the 70's or 80's in there. If the flow check is off I will probably hook up with Giles for a new one. I just hate the idea of 500-750 for a part I do not know is bad.
I am building the injector stand off another thread here with a 2 ton jack. Way too simple now that I have seen the photos.
THe way I see it it can only be IP timing, Injectors, IP, compression, fuel supply or return. The timing I have checked and rechecked with many looking over my shoulder.
the injectors are new but when I crack open the lines there is no difference with anyone injector.
The IP has never been worked on other than when I tweeked it by the book off this forum. THe star wheel was turned 1/4 turn, power screw up 1/4to 1/2, the pin turned to allow full movement for acceleration. But none of these cause white or grey smoke. They all make a lot of black smoke if done wrong.
Has anyone had IP leaks allowing air in the fuel stream? POssibly an internal air leak? Heck I just want to isolate the problem before dumping money where I do not need to.
-
.
I am going to redo the compression check and try it with a spoonful of oil. The motor is a 1.6TD from a Jetta installed in a Samurai. I must admit my luck has been far from good so far with this motor but when it runs nothing beats it.
Glow plugs tested at 35 ohms so I assume they are good.
A couple of random thoughts here:
- adding oil during a compression test on a diesel is highly 'not recommended"... because of the high compression the oil can easily ignite and lead to a a flying compression gauge or worse.
- 35 ohms seems pretty high for the glow plugs... iirc they should be an ohm or less each, since they draw in the neighborhood of 12 A at 12 volts.
-
THe block heater is used to preheat. It is 30-40 outside now and even my ugly Ford needs some pre-heat.
40 degrees is not that cold. Both of your vehicles should start up fine in those temps. With fair compression, and a properly functioning glow system, your car should fire right up. My old Rabbit with about 375-390 compression on all cylinders, would fire up (after a few cranks) every time, even at temps below zero (32 F). I never got stuck, even when it hit 12 degrees.
That your car will not start without the (electric) preglow, and it smokes white for a while really makes me think that the glow system is worth investigating. What year car do you have? There are some differences between the Turbo glow plugs and the NA plugs. From what I understand, the Turbo plugs are supposed to be SLOW GLOW, and need to have the correct relay. The NA are FAST glow, and need their appropriate relay. If the wrong relay is used with the plugs, then it can cause premature failure. Now, probably not 500 mile failure, but investigating it won't cost any money.
As far as testing the glow plugs, a simple test light will work fine, but you will need to remove the buss. But I'd assume the plugs are fine, but checking for power at the buss is a really good idea. I've heard stories of people buying used car's that wouldn't start. They cleaned the glow fuse contacts, and the cars started right up.
I'd venture to say that the IP is probably the last thing to look at, since they rarely go bad (unless leaking, and you'd see the leaks when it's running), and they're the most expensive part to replace.
As far as air leaks go, if you have a pre 1985-car, I'd say buy a new clear line from the fuel filter to the IP. You can buy new ones for cheap: Her's the PN: 068 130 309. Or, you can hold a flashlight behind the clear input line, and look for bubbles when the car is running, or bubbles heading back to the filter after it's stopped running. I'll doubt that you'll see any. If you do, then check all the filter/IP fittings, return lines, and make sure the filter is screwed on tight.
-
A couple of random thoughts here:
- adding oil during a compression test on a diesel is highly 'not recommended"... because of the high compression the oil can easily ignite and lead to a a flying compression gauge or worse.
- 35 ohms seems pretty high for the glow plugs... iirc they should be an ohm or less each, since they draw in the neighborhood of 12 A at 12 volts.
Indeed, the newer TDI's test at about 6-11 ohms, and they're basically the same thing. Here's a link about testing those (Make sure your multitester is setup right too):
http://forums.tdiclub.com/showthread.php?p=483553
I just checked some 1.6 NA loosies laying around the shop, and the resistance is that same as the TDI ones: about 8-11 ohms.
-
When adding the readings it totaled 35 ohms. My bad. The glow Plugs are great and do heat up well. All plugs individually measure between 8-9 ohms. Again they are new and should read like that. The relay is also new. I have never had any problems with the plugs but changed them out while I had things clear last time.
The white or gray smoke is continuos and never goes away even after the motor is hot. The compression test with oil is directly from the VW service shop manual. I know it can ignite and some folks even tell about how they blew their motors up doing it. VW has been using this as a test for over 20 years now so I can feel confident with reason I will be OK. The point of the oil is to seal the rings with liquid that is thick and will not slide away as the piston cycles. I normally use 40-50 weight iol as it takes a lot to ignite. WD 40 or penetrating oil would be a bad idea. The compression test done wet locates the leak as the rings or valve guides by noting a high rise in pressure for the rings bad or a small rise in pressure for the guides. With all four injectors out and oil with compression only on one cylinder I am not too worried even if it does fire off. The gage is rated at 1000PSI and so are the hoses and fittings. That is why we use Diesel testers not gassers.
Thanks for the help. Again I hope to get the time quick to run the compression test and check for more leaks. I will video the test just incase it blows up. If it is exciting I will send Waldon the video so he has something to laugh at.
-
You may as well send it to all of us, I think we all like to laugh :D While I have no experience using oil for a compression test I do know that the bentley suggests it so you probably are fine
What weight of oil are you running? that could give you the bad starts you are describing (needing to be plugged in at 30)
Has all of this happened over the same tank of fuel?
You can't really test glowplugs accurately with resistance or by continuity (test light) because they can fail in a closed state. Even if the glow plugs are new, if they were over torqued during install that alone can kill them right there, if not within a few hundred miles.
I think you have 2 separate issues though, one is the hard/ bad starting and one is the smoke. If it was the same issue it would go away once the engine warmed up.
Any word on your cooling system?
-
The compression test with oil is directly from the VW service shop manual. I know it can ignite and some folks even tell about how they blew their motors up doing it. VW has been using this as a test for over 20 years now so I can feel confident with reason I will be OK.
I only clarify this 'cause it's a potential safety issue... obviously we're all big boys and can decide what to do.
The VW service manual (the Bentley) actually specifically warns against doing the oil test on diesels... here's the text from the MK2 version:
Wet Compression Test (gasoline engines only)
To analyze poor compression and further identify the source of the leakage, repeat the compression test, this time with about a tablespoon of oil squirted into each cylinder. The oil will temporarily help seal between the piston rings and the cylinder wall, practically eliminating leakage past the rings for a short time. If this test yields higher compression readings than the "dry" compression test, the difference can be attributed to leakage between the piston rings and cylinder walls, due either to wear or to broken piston rings. Little or no change in compression readings indicates other leakage, probably from the valves or a failed cylinder head gasket.
CAUTION-
Do not attempt a wet compression test on a diesel engine. The oil in the cylinder may be ignited by compression pressure.
Again, I only clarify this since it's a potential safety issue. I personally do lots of things the manual tells me not to... like messing with the injection pump, for example ;-) YMMV I personally think the odds are slim... but that's their word on the subject.
-
Quoting my Bentley
to determine whether the piston rings are causing low compression, squirt a small quantity of SAE 40 oil into the low reading cylinder(s) through the injector hole(s), and repeat the compression test
- Volkswagen Rabbit, Jetta, Diesel Service Manaul
-
Cool... MK1 vs MK2 eh....
Dueling Bentleys at 40 paces, anyone ??!!! ;-)
-
maybe someone sued the Bentley company so they revised the mk2 version
-
Someone posted a PDF file on the shop secret manuel. It has great info and it also tells about the wet test. I think just like any other manual if the common shade tree mechanic was to do it with out knowing how much and how ofter it would be like lighting the propane heaterafter the spark failed without letting the gas vent out first. Many get lucky and some have to grow new eyebrows. 30 years wrenching and I still have to grow eyebrows sometimes.
I got my primary car running again today so I should be free this weekend for the test. I will post the pictures on the Suzuki site since I know how and link that to this site. In my mind this made sense???
-
Yes, pictures please !!!
-
OK here is a link to another post of the Samurai trucks with VW Diesels
There is a picture of the exhaust in the post.
http://bbs.zuwharrie.com/content/topic,75775.0.html
Later tonight I will pull apart the injectors and redo the compression check. Tomorrow I will post those results as well as pictures of the injectors and glow plugs.
-
Had the same problem. The smoke turned out to be unburnt fuel. Not black 'cause not over 2500 combustion temp. Just raw white smoke. Knowingly, ran some free fuel contaminated with gas. It was pretty diluted maybe 1 to 10... So the fuel was flat under power, but free. The next tank of real fuel the motor started chug'in and smoke'in, white at idle. Random miss fire. Up top it burned clean (almost to clean), smoothed out. Took the top off the pump and found the gas worked as a solvent. It had broken free the thin layers of what looks to be the fuel staining on the inside of the pump. I ended up taking the pump apart to clean complete. I think the problem was in the very top off the pump. The star looking wheel with the four weight, maybe the governor, had some gummy residual under the weights that would not let it to retract all the way. U sound capable, pull the pump apart. I have saved a few pumps by going in a finding something wrong. Good luck
-
I suspect not wanting to crank has more to do with the low compression you have. You don't mention what machine work was done, Did it get bored and new pistons/rings ? Valves faced or seats cut? Did the shop have the head? You're low on compression for some reason now, if it was bored and honed the honed crosshatch may be too rough allowing blowby and needing additional breakin time, if the valves and/or seats were reworked and they didn't have cam & followers or didn't check the new installed height you could be loosing compression charge past the valves..but is easily checked as your valve clearance standard procedure...you mentioned they rebuilt the injectors also, I'd atleast check the pop pressure and make sure of a spray not a stream. Bosch nozzles are very reasonable on ebay if they only cleaned yours.
Oil test is ok with common sense, but liquids don't compress hence the warning... only use ~1 cc of oil, on FLAT GROUND so it can seal ALL around the ring and give the oil time to get there... find something similar to a piston and watch how long it takes oil to runoff..where it would rest on the top rings where it does the sealing. If you find the comp has come up significantly the rings aren't doing their job, I doubt this is a pump prob if it will make enough power to drive reasonably but with white smoke...
You can tell a lot about leakdown by placing in 3rd or so gear on a hill with a partner and use a hose to listen into the crankcase through the oil fill and through the intake manifold, push downhill just enough to hear the air hissing from leakdown. Exhaust leakage is a little harder to hear, and for safety sake stay on the uphill side with the end you want to listen to.
-
Motor work was complete machining. The head was checked hot for leakage and the valves were ok. The cylinders were cut and I do not know the ring size used. I am heating up the garage now so I can start work. I luv lazy sundays. The way she is running now I have no power and a lot of smoke. New post in a couple hours.
-
Hate to sound like an old fart.... In my day the machine shop was always right. I never questioned a machinist. Hi sopinion was based on exact measurements and precise machine work. Everything was written and documented. Quality German in SoCal and their machinists are worthless. 7 shop reworks 4 heads and still I have a pile.
New plan;
Compression test is 250 dry and 450 wet. Sorry waldon even at those numbers no big bang show. Glow plugs look new and injectors have minor carbon on them. Compression rings?????? TOAST.
I will now have to rebuild the motor myself and find where the machinost did not measure or cut. At least the heads are not blown or cracked. Something was not or has not been checked with the cylinder bore. Whether it is out of round, tapered, or just cut sloppy the rings did not set and I never achieved full compression.
So if any real machinists are out there and can tell me options for cylinder bore as well as specs for max cut and resleave requirements I will be very happy. Possibly I have a shop in LA (78 mile drive ) or Las Vegas ( 188 mile drive with dinner and a show ). If anyone knows a better shop let me know. I live in Big Bear 92314 for Google maps.
The Vegas shop is a part time neighbor of mine and is supposed to be the largest in Nevada. Don't know the name but he drives real nice cars and his toys are tops so at least he has made good bank for the past 30 years he has run it.
-
That sucks. Keep Total Seal in mind for rings. You can get a whole set, have your second ring machined or buy just the 2nd rings from them.
-
Have you taken the head off yet? Even a cheapo $30 dial bore gage will help you a LOT.
http://item.express.ebay.com/2-6-BEST-CYLINDER-BORE-GAGE-DIAL-0005-GAGES-GAUGE_W0QQitemZ260204505403QQihZ016QQtrZexpQQcmdZExpressItem
or search dial + bore on ebay.
If they bored it and used standard pistons they will surely chew the bore and rings...from the piston rocking
Machinist used to mean something... nowdays it often means HACK
If the machine shop is reluctant to discuss surface finish and fit tolerance with you it's the WRONG shop. If the music is louder than the machines it's the WRONG shop.
The first indication was their thinking 500 psi is too much, but a diesel or gas bore & hone job should be something any shop should get right and if you return to discuss it with them it's something you should put in their lap.
G'd luck with the Sammy, I drive a TD Isuzu Trooper!
-
In Ca, the land of the lawsuit, I would think you would have some recourse for a crappy rebuild.
-
Well I opened it up and it looks real good. The pistons are oversized so I think it is at max bore. Cylinder walls are clean and show no signs of taper or chatter. Pistons are sized at 76.96. I guess that means I need 77.00 rings or the 50 over set.
BTY The heads also look real clean. Minor cracking in the normal spots between valves.
Head Gasket is a 3 hole gasket. I still need to measure the piston height to see if that is right size.
-
This sounds like timing, specifically cam/crank.
On your flywheel is there a large notch and than a few degrees past that a small "0" mark? If so you have a gasser flywheel and your crank is out 6 degrees.
-
I have an ACME kit installed in a Suzuki. I checked the flywheel markings with a dial gage on #1 piston the day I installed it. Dead on. The flywheel is a custom cut/ adapted wheel.
Many issues with the machine shop that was working the motor. I am now just bumping the post to the top so I can keep some of ya informed. Looks like the rings are well worn or they used 40 overs instead?? Not sure how rings could have worn in 5,000 miles with out other issues too. Anyways I am waiting for the 50 over rings to come in then I will post the final results.
-
OK so my pistons are marked as 76.96 and the bore measures 76.92. I am assuming the pistons are 50 over and I just am not measuring the bore right. I am still waiting on a set of inside mics to get an accurate measure. Witha digital Harbor Freight top notch caliper I get 76.92. Any thoughts on rings. I think it is going to be 50 over rings.
Also has anyone resleeved their block? With the bore at its max I am considering a resleeve. Of course I need to find a shop too but I would like to hear if anyone had any luck with it first.