temp? problem Please help!!!!!

kiddkatkiddkat Member Posts: 1
I have a '91 Silhouette that recently has started to stall out at the first stop getting off the freeway or when it gets hot. I've tried 2 separate mechanics and both tell me there is no problem they can diagnose. Anyone have a similar problem???? I have to fix or sell it and can't afford to pay yet another mechanic to tell me there's nothing wrong.


  • rich1813rich1813 Member Posts: 8
    I had a 95 Olds Delta 88, 6 cyl. When it got hot, it would stall. I had to let it cool then it would restart OK. Turned out to be the crankshaft position sensor. For that car, it cost under $5 dollars.
  • rich1813rich1813 Member Posts: 8
    Have a 2003 Old Silhouette. Seems when it gets a car wash, either by myself, or in auto wash, my power door locks act up. Normal operation for this van is when putting in gear, all the doors lock automatically. When it gets wet, It'll work first time, then you drive the car and the door locks will either repeatly open several times then stop and stay open, or it'll lock when placed in gear, then the locks will repeatly try to lock several times. Changed the front pads, and when compressing the cylinders on the calipers, some brake fluid got pash my rags in the master cyl. It dripped about a tablespoon on the garage floor. The next day the power locks acts up trying to unlock as per above. Very intermittent, and dealer can't diagnose since it is difficult to get it to act up for an appt at the dealer. Anyone have a similar experience or suggestions. Thanks.
  • tawnymtawnym Member Posts: 9
    I have just bought an 1999 silhouette and I have had it a week and it is now sitting in my garage waiting to be worked on. I loved the van when I test drove it and then I took my dad to test drive it the next day he also thought it was a really good van. It got hot a couple days ago. Checked the oil and it has water in it. We are thinking that the head gasket and probably the heads are bad has anyone had this problem with one. The van drove and rode like a dream before this happened.
  • rich1813rich1813 Member Posts: 8
    I have owned a 2001 and a 2003 Olds Solhouette. The intake mianfold gasket failed on the 2001 at 34000 miles and the rear head gasket failed also. Both were replaced. I caught the leak early and after one drip of coolant was seen on my garage floor. The intake gasket was replaced, but after 3 days, still saw the drip. Had it towed to a GM shop for a pressure test, and they confirmed the rear head gasket was leaking. On my 2003, the intake manifold gasket also failed, this one at about 60K miles. Discussed it with the GM mechanic, he indicated the hole pattern on the gasketes weren't robust and he thought the failure was due to thermal cycling over time, and the gaskets probably last 60 to 80K. Both of mine started to leak when we had a very cold snap, but it had been through several seasons. Both of my leaks were external leaks and the coolant went out, which the GM mechanic suggested was more typical of the intake manifold gasket failure, assuing one would catch it early. My head gasket leak was diagnosed with a pressure test. Not sure if that is that effective on an internal leak as it was for my external leak. If it's the heads, the mechanic checked to make sure the head the gasket failed on wasn't warped which it wasn't, and which is checked when the engine is broken down to get to the head gasket. Perhaps some other competent mechanics out there can comment on an appropriate diagnodsis for internal leaks. In any event, if you get get the head or the intake gasket repaired, make sure you get the system flushed in case there's any sludging from the system taking on oxygen and thickening the DexCool. If the system was converted to the green coolnat it isn't as sensitive to oxidation. Might also want to get the unit scoped for hot spots, had that done on my rad on a different car. Not sure how useful it would be on this van, but would do it after the repair.
  • tawnymtawnym Member Posts: 9
    Thank you for your advice I will do the flush as you say, I've been so upset about this situation. I am a mom of three and I am in college so money is tight, luckily I have a dad that is good at this kind of thing. But should I be worried about this in the future with this van? It wasn't converted to the green it has the pink/red coolant. Thank you so much for your fast response. How do you like the van other than the repairs you have had done on it?
  • rich1813rich1813 Member Posts: 8
    We like the van. Gets the 17mpg in the city, and we actually get 27 on the highway. Good size for the kids.

    Some mechanics will tell you to convert to the green coolant after a flush. Some will say it's the gasket design. I think the DexCool is a more sensitive coolant if you have a leak since it thickens and sludges with the air. Thus the need to flush once you see a leak. On your car, the real question is what's leaking. The intake manifold gaskets are known to be issues on this and other GM vans. The last one I replaced, the mechanic said GM tried to fix the issue by putting in a more durable gasket, so that's good, but he also gave me a life expectancy and he felt the intake gasket failed because of where the one bolt hole was placed and how much plastic encasement was left to hold the O-ring. Once the plastic holder became soft, the o-ring doesn't seal as he put it. GM as he suggested has tried to redesign the palstic part, and I think he mentioned they went to a metal sheath to reinforce the plastic, but he still didn't think it solved the bolt hole placement. In any event, I have no idea if what he was saying is factual of not. While he didn't think the DexCool itself was the issue, my opinion says the DexCool needs to be watch more carefully thyan the green coolant if it gets low. The DexCool is an OAT or organic acid technology, which is said to be a better corrosion inhibitor, but that is if it's wetting the metal parts on your coolant system. If it isn't, I've read that it isn't as good as the green since the green forms a silicate film on the metal, which will still provide corrosion inhibition if not wetted. But the down side is the silicate film isn't as ggod a heat conductor, so the system can run a little hotter just from that, plus I think the DexCool has better thermal conductivity in the coolant itself. Some people really like the green, some say stick with the DexCool since it's tough to guarantee all the DexCool is flushed out even after a flush. The Dex and the green coolants are not compatable. On my first van, when it had the intake manifold gasket replaced, they actually recommended in flush and convert it. You should get of course an oil change, and my trusted mechanic thought it'd take about 3 oil changes to get the water out of the oil system if the two mixed. Anyway, good luck with it, hopefully there wasn't more sludging in other parts which could cause corrosion.
  • tawnymtawnym Member Posts: 9
    Thank you again. I really do like the van myself, I have a dodge grand caravan which has been through 3 transmissions @ 1800 a piece the last one has lasted me 3 yrs but it is now acting up so I didn't want a dodge again, they are know for trany problems in all thier models. We go to disney every spring and I wanted something as roomy as the dodge and the only one that was, was the olds or chevy. I myself have always liked GM's the best. It does make sense to flush the oil so much as well. Got to make sure all the moisture is out. I do believe that I will change to the green coolant, the only other thing I don't like about the system is the burping you have to do. Seems like you can have a good chance of having an air lock, have you had a problem with any air locks? So when I get a new gasket set it will be the kind that GM has improved? Should I make sure that it isn't the cheep version? lol I normally go with the cheepest but for something like this I won't, or should I get it from a GM dealer to make sure I get the improved gaskets? Thank you again for all your help and information.
  • lalalandlalaland Member Posts: 9
    This van is the biggest piece I've ever owned.

    But all the temp problems, for me, always go back to the head gasket. Been replaced twice. :lemon:
    For the record, I got my settlement check yesterday! Yay!
  • nofanofthevannofanofthevan Member Posts: 1
    I agree yet I keep sinking my money into it. We also had to have the head gasket replaced. Now the heated seat does work, the gas level sensor is gone, air conditioning kicked the bed and the windsheild wipers are a nightmare! Wish GM would own up to it and give us our money back, that would be nice!
  • cjr53cjr53 Member Posts: 1
    There is a generic problem with the gasket between the lower intake manifold and the heads. The FIX is to pull the upper & lower intake manifolds and replace those plastic gaskets with the tiny rubber insert with a good gasket made by a major gasket company (Felpro or equivalent) that is the premium gasket. It has a steel gasket form with full size rubber seals. Costs about $75, if you've done this work before, it is 2 full days of work. First time it will take longer. Take lots of pictures of every connection, hose, wire, and routing from multiple angles so you can figure out how it all goes back together.
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