UIM. Confirmed, and with Pictures.
#1
UIM. Confirmed, and with Pictures.
My brother today told me that he couldn't get his car started earlier in the morning. He would turn the key and the lights would dim and the starter would just click. The car wouldn't start. He thought he had a bad battery so he had the car jump started. He said it cranked, but very very slowly and after a few cranks finally started. When the car was finally started, I guess a really strong smell was coming from the exhaust but he said he didn't know what it was from. I looked at the car today and the coolant overflow tank was bone dry. I also noticed that when the car is started after sitting for a few hours that BLUE smoke is coming from the exhaust, along with the sweet smell. I told him not to drive it because it sounds like a bad UIM, but the car is still driving just fine. I checked the oil and it'* not milky or anything so I'm not sure what'* going on with it. Are there any other additional tests that I can do to try and figure out if it'* the UIM or not? Thanks!
This is on a 2000 SLE for those who don't know.
This is on a 2000 SLE for those who don't know.
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#4
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A tech at the pontiac garage I go to said that if the UIM itself (or a gasket) fails, you can pull the air intake tube off and see straight through the throttle body for signs of coolant. If the wall of the UIM break through to the coolant passage at the EGR stovepipe you can see coolant spraying into the intake while its running, he said. Top the coolant off right to the line and watch it, it may have used up slowly and wasn't checked for a while.
Keep in mind the plastic LIM gaskets fail also, but I don't know how you would check that for internal coolant leakage to the intake. Either way I would think that serious coolant in the cylinders should file a plug quick and cause misfiring (?)
Keep in mind the plastic LIM gaskets fail also, but I don't know how you would check that for internal coolant leakage to the intake. Either way I would think that serious coolant in the cylinders should file a plug quick and cause misfiring (?)
#5
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The symptoms you describe, low coolant, hard start, sweet smell in exhaust, strongly suggest that the UIM or LIM gaskets have failed and the engine is ingesting coolant. Please read: http://www.bonnevilleclub.com/forum/...e=article&k=38
With internal coolant leaks, especially if the car has been run for any length of time, there is a good possibility that coolant has found its way into the crankcase and oiling system. Coolant will attack the bearings in the engine. A cooling system pressure test will confirm an internal leak.
If you suspect that the oil has been contaminated with coolant, I would advise draining the coolant from the car, and flushing the oiling system as soon as possible. A method is described here:
IMO, the best off-the-shelf fix for the L36 is the APN upper kit mentioned and linked in the above article, GM aluminum frame lower intake manifold gaskets, new coolant elbows, and flush and fill of the coolant system to remove the Dex-cool and replace with "mixes with any color" (G05 spec) coolant. If you have the tools and mechanical aptitude, you can make these repairs yourself for about $200.
With internal coolant leaks, especially if the car has been run for any length of time, there is a good possibility that coolant has found its way into the crankcase and oiling system. Coolant will attack the bearings in the engine. A cooling system pressure test will confirm an internal leak.
If you suspect that the oil has been contaminated with coolant, I would advise draining the coolant from the car, and flushing the oiling system as soon as possible. A method is described here:
One way to minimize coolant damage to the bearings is to flush the oiling system with fresh oil and a new filter. You must drain the coolant first, however, so that more coolant does not contaminate the fresh oil. After draining the coolant, pull the spark plugs and turn the motor through at least one revolution by hand, then use the starter a few times to remove any coolant that might have filled a cylinder with the piston down. Leave the spark plugs out. Drain the oil and refill the crankcase with wal-mart 5W-30 and replace the filter with a cheap one. With NO COOLANT in the engine, the safest way to flush the system is to turn the engine over with a big 1/2" drill. Buy a cheap, 1/2" drive extension; cut off the female end; grind some flats on it if you like, and chuck it into the drill. You need to remove the RF wheel and splash shield to give you access to the crankshaft bolt that you need to turn the engine this way. You can turn the ignition key to run while you spin the engine with the drill to monitor the oil pressure if you like. By pumping fresh oil through the system as soon as possible, you will minimize any possible bearing damage.
When you have pumped fresh oil for a few minutes this way, you can then drain the oil and remove and change the filter for another cheapo for the next flush you will perform after the repairs are made.
When you have pumped fresh oil for a few minutes this way, you can then drain the oil and remove and change the filter for another cheapo for the next flush you will perform after the repairs are made.
#6
some bad news.. I checked the coolant and oil in the daylight today and the radiator is completely empty but there is a TON of oil residue all over the radiator, and teh radiator cap. It looks like brown/black sludge in there. The oil does in fact look milky now as well. The stupid car didn't even give a low coolant warning or anything.
#7
Here are some pictures of the upper intake manifold and the lower intake manifold gaskets.
As it turns out, the UIM was actually in pretty good shape. the build date was 11/10/1999, the car is a 2000 so it was definately the original. The new intake is a Dorman "performance" intake and looks to be slightly heavier built than the original. But, Like I said, the coolant leaking problem wasn't the UIM, it was the lower manifold gaskets that had deteriorated to the point that in some areas the gasket was completely gone!
First picture of the LIM gaskets... noticed how warped it is in areas:
here is a close-up of one section. Large chunks of the gasket are missing even. My mechanic told me that they were already gone when he pulled the gaskets off.
This is the upper intake manifold itself. The EGR passthrough looks fine. There wasn't any warpage at all, I just had it replaced anyways just incase though.
It probably could have been saved and reused, I was just uneasy about keeping it since it was almost 8 years old!
Here'* a breakdown of the cost
Dorman intake manifold: $179
Felpro Lower intake gasket set: $50
GM plastic coolant elbow: $15
Valvoline 5-w30: $10
oil filter: $4
2 gallons DEXCOOL: $22
Labor: $131
As it turns out, the UIM was actually in pretty good shape. the build date was 11/10/1999, the car is a 2000 so it was definately the original. The new intake is a Dorman "performance" intake and looks to be slightly heavier built than the original. But, Like I said, the coolant leaking problem wasn't the UIM, it was the lower manifold gaskets that had deteriorated to the point that in some areas the gasket was completely gone!
First picture of the LIM gaskets... noticed how warped it is in areas:
here is a close-up of one section. Large chunks of the gasket are missing even. My mechanic told me that they were already gone when he pulled the gaskets off.
This is the upper intake manifold itself. The EGR passthrough looks fine. There wasn't any warpage at all, I just had it replaced anyways just incase though.
It probably could have been saved and reused, I was just uneasy about keeping it since it was almost 8 years old!
Here'* a breakdown of the cost
Dorman intake manifold: $179
Felpro Lower intake gasket set: $50
GM plastic coolant elbow: $15
Valvoline 5-w30: $10
oil filter: $4
2 gallons DEXCOOL: $22
Labor: $131
#8
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Dorman intake manifold: $179
Felpro Lower intake gasket set: $50
GM plastic coolant elbow: $15
Valvoline 5-w30: $10
oil filter: $4
2 gallons DEXCOOL: $22
Labor: $131
Felpro Lower intake gasket set: $50
GM plastic coolant elbow: $15
Valvoline 5-w30: $10
oil filter: $4
2 gallons DEXCOOL: $22
Labor: $131
Not the GM aluminum gaskets?
Do a search on the problems with elbows. Billboost37 and I as authors. In the same week. Try Dorman elbows.
2 gallons of DEX? NO! Get it flushed out and replaced with Prestone Long-Life Dex compatible.
You are only putting a temporary bandaid on this car with that list.
#10
I didn't do the work myself, I had a trusted mechanic do it. I would do it if I had either the time, or a place to do it, but unfortunately, I have neither. Repair time was crucial, which is why he went with the parts he did. We didn't have time to order anything other than what he got. I look at it this way, the stock parts made it to almost 80,000 miles and seven years. I know my brother is not going to have this car even in another two years. I'll pass the word along to him about the coolant, he'll probably do it once he has some extra cash saved up. (not right now.) For how much it [didn't] cost, and the low repair time, I couldn't of asked for more. I can't afford not to have a car to drive.
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Paul1981
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12-21-2007 10:05 PM