Loosing Antifreeze

rgjones21

Bought 1999 Venture Minivan used with 7400 miles on it almost three years ago now. Up until now it has been a pretty good vehicle with only some minor warranty repairs. However it now has almost 60,000 miles and about 2 months ago it started loosing antifreeze out of the reservoir and during this time period added almost 1 gallon. Since we could see nor find no leaks we took it to the shop to see if problem could be located. Alas the coolant has been seeping into the engine,(evidence by white gunk on oil cap, but no sign of water in the oil) suspect through intake or head gasket and it appears the engine may be gone if bearings are wiped. Don't know yet because had it towed to Chevrolet dealer who is going to check it out on Monday. Since the 36,000 mile 36 month warranty is out we are worried we will have to pay for new engine. Anyone else had this problem? Discussion with shop and Chevrolet dealer indicated this engine is known for this. I called the consumer service number but have to have it evaluated by Chevrolet dealer before they will tell me anything.

swschrad

white gunk under the oil filler cap is so often plain old condensation from the engine never getting warmed up fully in stop-and-go driving that seeing it is no sign of anything. if you have water in the oil, it's a serious milky and/or blobby mixture.

having said that, it seems like every carmaker is trying to hide some head gasket or manifold failure problems in at least one of their engines now, and they should all be roasted on a spit for that until they have made good every single bloody bad engine they put out there. purely no excuse for it.

good luck on yours... try for a customer satisfaction payment from the chevy zone office if it turns out you, too, are hosed by a gutless gasket on an insufficiently-cooled engine.

0patience

As was stated, the milky color on the cap may be from condensation.
If it is the V-6, then I'd put money on the intake gasket leaking externally down the side of the block. This will only be evident by presure testing the cooling system and checking the rear of the engine where the bell housing meets the engine. It will either leak down onto the starter or the side of the block. Or it will leak down the front of the engine. Also check the weep hole of the water pump.
All of these leaks are barely visible under pressure, let alone with the vehicle sitting.
If the gasket lets loose and leaks internally, the oil in the pan will be milky.

trackerdk

I have spent the last week and a half with the same problem (leaking intake manifold gasket). After many phone calls to GM customer service they finally agreed to pay for half of the repair bill seeing that my van is out of warranty (45,000 miles). The women I was talking to didn't even know what an intake manifold gasket was. I have searched other sites and found this to be a re-occuring problem and feel GM should step up to the plate and pay for the full cost of this problem.

gilgum

Can you believe a 99 Suburban with less than 30,000 miles on the engine would have a bad intake manifold gasket? A mechanic told me they are replacing 3 or 4 of these per week and yet GM is not notifying owners and extending the warranty to cover it. Is it any wonder they have to discount their vehicles so much to compete? My vehicle has a 5.7 liter engine, is not even 4 years old but exceeds the 36 months so is out of warranty according to GM. Unbelievable.

swschrad

for holding the failure out until the warranty went away.

cruzer1967

My 99 Alero has the same problem and I only have 39,000 miles. My reseearch tells me that this is common on GM's 3.1/3.4 V6 engines. You need to see this guys story about his 99 Chevy Venture at www.gm-v6lemons.com

swschrad

guess engines are considered a service-replaceable item now, folks, just like turn signal bulbs and air filters. so be sure they take the cost of the engine off the price when you buy a new one next time.

0patience

I have to tell you, while the problem is true and I have personally been affected by it twice, if I were the dealership that this person has flamed on his site, I would be seeking legal action against this person. While this person's intentions are good, he is going about it all wrong. First off, the dealer's hands are tied.
If the manufacturer will not reimburse them for the repair, why should the dealer repair it for free? The answer is, they shouldn't.

Don't get me wrong, I am one of the strongest consumer advocates you witll find for honest automotive repair, but put the blame on this one where it belongs.

I have had the intake manifold replaced on my wife's 99 Lumina 3 times. All 3 under warranty.
The first one under the manufacturer's warranty at 33,000 miles, the second one under manufacturer's warranty at 48,000 miles, as an ongoing problem. The third one a 68,000 miles on the extended warranty I paid for.

swschrad

when we presumably know more about sealing technology than we did in the 1950s. I have a sneaking suspicion that gasket and sealer improvements are being used to cover engineering to a certain mile marker, say 95 thousand just to start discussion, and the fails are because there is no margin for any production errors or seedy sealant.

it would be the old so-called GM 350 "diesel" all over again, in which two more head bolts on a gas engine supposedly made it possible to burn diesel in the chevy short block. didn't work. couldn't work. but they sure tried to stonewall through.

alcan

That was a modified Oldsmobile 350 block. Replaced more broken main bearing cap bolts on those lumps than I can count.

jimmycheese

My 98 Venture started losing coolant at 55000. I kept adding and adding. The shop I use tried to snug down the bolts to the intake manifold, to no avail. They did replace the gasket at 65,000. No more leaks yet (91,000) but alot of other problems. It is too bad because I love the van.

andre1969

...that GM used Oldsmobile blocks as the basis for their Diesel instead of the Chevy block! The Olds 350 was the strongest of them back then, so as badly as it took to Diesel mods, a Buick or Pontiac would've been worse, and a Chevy, truly devastating!

As for these coolant leaks nowadays, well don't the 3.1/3.4 and 3.8 use a plastic intake manifold? Seems to me that's just asking for trouble, since plastic does all sorts of fun things like warp, crack, get brittle, etc.

Swschrad, I do believe they actually have learned a lot about gaskets and sealing technology since the '50's. The technology has advanced greatly since then, but unfortunately sometimes it gets focused more on finding ways to make things cheaper, instead of better!

dhoff

0patience, maybe you can give me some advice here. I have a 99 Nissan Quest with about 84,000 miles. I have a slight external coolant leak. It's not even really a leak, more like seepage. I can see green gunk near what appears to be the junction of the intake manifold and the front head, under the intake manifold. There are a number of coolant lines that run under the manifold, and possibly through it as well, and I can't see exactly where it is coming from.

I have to add a splash of coolant every 4-5 months. It's not causing any problems that I can see, other than some of the gunk is starting to get into one of the spark plug wells.

I'm thinking of adding some stop leak to the radiator, since it doesn't seem worth the effort or expense to fix it. Is there any downside to this? Can this harm the cooling system, or should I jsut live with it?

Dave

edwardn1

...according to the bottle it is added to the radiators at the factory by the major makers to prevent leaks. I have a hard time believing this. I,ve used both alumaseal and barsleaks and found the barsleak to be gentle and not block anything. I know people that put in the barsleak before they even have a leak.

swschrad

sure it has, and for a 200% improvement in pressure/temperature resistance, for instance, there is always an engineer who figures they can squeeze 300% out of it. those are the guys who leave us with head gasket and intake gasket issues. their names should be on the block, along with their home phone number, so we can congratulate them on making an engine that goes 20,000 before turning into a paperweight.

armtdm

No. If that is all you are losing do not take a chance. I jsut did this in two cars and one of them needed a new radiator a month later, the other doing fine. An external leak hurts nothing, do not take the risk, just add coolant every few months. It may get worse or it may just stop on its own.

Not worth the risk of a sealer, only as a last resort to a major repair.

swschrad

with hotter engines and skinny little coolant passages, I tend to agree, stop-leak is only for emergency repair purposes.

0patience

DO NOT use sealers.
To my knowledge, Cadillac is the only manufacturer that recommends any sealer and ONLY their sealer.

Ok, here's the deal. You can easily, with little effort, locate the source of the leak.
Once the leak is located, it can then be fixed properly, as the leak will only get worse.
All you need to do is get a UV Leak Detector light, I have one from Tracerline, TP-8600 Blue Max™ Penlight and one from Lisle products, 36000 Flexible UV LED light. These lights are around $40. If you can't find them, e-mail me.
Then go down to your local part store and get a bottle of Coolant Leak Detection Dye and put it in the radiator.
Run the vehicle for a while and then use the IV light to find the location of the leak.
Here is an article on how to use the leak detection light and dye.