is this LIM/UIM gasket failure?
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For a while now, stopping quickly after starting the car in the morning, a puff of white smoke comes up from above the left fender. And Ive noticed recurring puddles sitting on the LIM shown here, when engine is both warm and cold. I always use form-a-gasket along with the paper gasket on the water pump flange so im 95% sure its not coming from there. Below you can see obvious water marks on the aluminum. This pic was taken an hour after running. What made me post this was the car had sat for two days and when i went to park in the same spot there was a small puddle of coolant.
AREA #:
(1). Always water there, the most there of them all
(2). I loosened the bolt and put form-a-gasket on it then tightened it, havent seen moisture there since
(3). Appears to be moist there alot.
(4). Sometimes moisture, obviously evidence in the watermarks.
![Name: DSC01093.jpg
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The 1st area has a bolt in there too and i also tried the trick i used in bolt 2, but no dice.
This leak isnt large enough such that i have to add coolant, coolant level remains same for the last year.
Advice/Comments? Thanks Guys.
AREA #:
(1). Always water there, the most there of them all
(2). I loosened the bolt and put form-a-gasket on it then tightened it, havent seen moisture there since
(3). Appears to be moist there alot.
(4). Sometimes moisture, obviously evidence in the watermarks.
![Name: DSC01093.jpg
Views: 49
Size: 72.5 KB](https://www.gmforum.com/attachments/1992-1999-91/40492d1501293995-lim-uim-gasket-failure-dsc01093.jpg)
The 1st area has a bolt in there too and i also tried the trick i used in bolt 2, but no dice.
This leak isnt large enough such that i have to add coolant, coolant level remains same for the last year.
Advice/Comments? Thanks Guys.
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Originally Posted by wjcollier07
You...don't...have a L36? Or do you...
That failure is only applicable on the L36.
That failure is only applicable on the L36.
I ask because i often find myself roaming over threads with LIM/UIM gasket failure as the title. Is it purely an L36 problem, or just that it is a known issue with the L36?
The L36 and L27 i know are different (my dad has a 98SE), but still close enough in design that i thought that gasket failure is whats causing this moisture/water to collect.
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John, LIM gasket failures are applicable to the Series I also, but are nowhere near as common. I replaced mine on my '94 because they were seeping between the LIM and head near the valve cover like Grey'* #3 marker was.
Grey, with your mileage, it doesn't surprise me that they are leaking. I pulled a LIM off of a 225k L67 in the U-pull-it yard here, and the LIM gaskets looked as bad as a L36/S2 L67'* and showed signs of leaking. You definantely have a leak, but it could just be loose bolts. Check to see if they are all tightened to spec, as they can loosen up and cause leaks.
Grey, with your mileage, it doesn't surprise me that they are leaking. I pulled a LIM off of a 225k L67 in the U-pull-it yard here, and the LIM gaskets looked as bad as a L36/S2 L67'* and showed signs of leaking. You definantely have a leak, but it could just be loose bolts. Check to see if they are all tightened to spec, as they can loosen up and cause leaks.
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Grey..how much RTV did you use when installing the thermostat? RTV in places like this can actually keep the gasket from sealing and cause a leak if the surface it'* mating to isn't 100% clean. RTV won't stick to oil. Therefore if there is enough RTV to keep the paper from making a good seal and oil...you can have a pressure leak.
Your pulling of the bolts and adding goop to them is a good idea. Those bolts are known to weep if sealant is not applied when gaskets are changed or over enough time.
Your pulling of the bolts and adding goop to them is a good idea. Those bolts are known to weep if sealant is not applied when gaskets are changed or over enough time.
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Originally Posted by BillBoost37
Grey..how much RTV did you use when installing the thermostat? RTV in places like this can actually keep the gasket from sealing and cause a leak if the surface it'* mating to isn't 100% clean. RTV won't stick to oil. Therefore if there is enough RTV to keep the paper from making a good seal and oil...you can have a pressure leak.
Your pulling of the bolts and adding goop to them is a good idea. Those bolts are known to weep if sealant is not applied when gaskets are changed or over enough time.
Your pulling of the bolts and adding goop to them is a good idea. Those bolts are known to weep if sealant is not applied when gaskets are changed or over enough time.
Well after the car sat another 24hrs, no puddles and no moist looking areas. Perhaps it is a pressure leak. Ill be observing this much closer now, opening hood before and after using her.
Many Thanks for your input guys.
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