2001 Silhoette Coolant Leak

[cowrack]

Hi, I believe I can't continue to update my older thread, so I am starting a new thread.

I am getting a coolant leak from the drivers side of the engine. More specifically, from right around the housing for the thermostat. (I finally found the manual for this vehicle). Now, I do not believe this is coming from the sensor, and I can't see it is coming from the housing or the seal between the housing and the engine, but is there anything else coolant related in that area? It appears just right below the sensor, but I can't find a clear source. I can smell a light burn, and it does drip down to the floor overnight, maybe 1-6 drops.. It isn't horrible yet. i don't think this is the intake gasket, but I don't know the symptoms of those (other than possibly milky oil). Any help? I know most likely it is the housing around the thermostat, but it just doesn't appear to be. Does anyone have any good procedures for replacing the thermostat? (I am sure it is fine, but the gasket could be leaking).

Thanks

Jamie

[Milo2001]

Mine did the same thing for about 2years. Then one morning my wife called and said there was a river of anitfreeze coming out from underneath. When I got there, it sure was the intake manifold gasket. Drove it home with the heat on high and the radiator cap loose. $900 mechanic bill later no more leak. They also changed the oil, flushed the rad and changed all the hoses and thermostat. Van had about 95,000 miles on it. Other than that the van has been real good to us.

Good Luck

[stregisfalls]

I thought olds stopped production on the silhouette in 1999?

[rockwood84]

you have to take the throttle intake hose off to get to the thermastat or sensor. but also the cross bead of rtv goes across the intake in this same area could be just a bad o ring that goes on the thermastat. if you put a new thermastat in it do not put one made in mexico in it as it will not open when it gets hot. and as for as i know g.m. build the ****lo's up to 2005 when they came out with the uplander.

['97ventureowner]

Originally Posted by stregisfalls

I thought olds stopped production on the silhouette in 1999?

Originally Posted by rockwood84

as for as i know g.m. build the ****lo's up to 2005 when they came out with the uplander.

Actually the Silhouette was produced up until 2004 when GM phased out the whole Oldsmobile line. The Uplander debuted in 2005 and was sold alongside the Venture. The Venture was discontinued after the 2005 model year to be replaced by the Uplander.

[94 Jimmy]

Try a can of Alumiseal. It's a great stop leak and might get you through until spring when it warms up, or longer if your lucky. This engine has problems with coolant leaks and head gasket problems. They're not too difficult to fix, but it requires rotating the engine forward to get at the back. Let me know if your thinking of it and I'll go into how it's done.
Also check your antifreeze and oil to see if either is mixing with the other. Water in the oil looks like dirty mayonaise and of course oil in the water looks like an oil slick.

Good luck
94

[mmusa]

hi,am sure your problem is 100% "intake mainfold gasket". fix this early dont late, now it will cost you around 450$ to change gasket+labur. or if you late it will cost gasket+damege inside the engine"camshaft +intake mainfold". that what happend to me. good look.

[zyzzle]

Originally Posted by mmusa

hi,am sure your problem is 100% "intake mainfold gasket". fix this early dont late, now it will cost you around 450$ to change gasket+labur. or if you late it will cost gasket+damege inside the engine"camshaft +intake mainfold". that what happend to me. good look.

I agree it sounds like an intake gasket - this engine is prone to that. More like $1000.00 to fix at a dealer. Really togh job to do.

[catesja]

Intake gasket My Montana did the same, and I took it in and was diagnosed as intake manifold gasket. They were bad quality that was put in originally. I did the job myself in my driveway in the middle of December a year ago. Took about 2 days to make sure it was done right, cost about $200 in parts.

[kidfam]

My 1998 Olds Silhouette is streaming water somewhere from the block/heads under the front heat shield. Are there freeze/expansion plugs located under there that may have blown or rotten out? My Haynes manuals says nothing about freeze plugs.

[3800wattvan]

1999 olds Silhouette. Intake manifold gasket. When I finished tearing the whole thing apart I found that the bolts were simply getting loose on the drivers side. Replaced it anyway. Progressively got worse. No water got into my engine oil.

[Cressidaadr]

Maybe you got lucky and no coolant got into your engine oil. Just because you cannot see it in the oil does not mean the oil is not contaminated with coolant.

My oil looked fine and there was no noticeable change in oil level but there was sever contamination that I only found after doing an oil analysis.