Engine Dead at 49K Please Help!!

saubouin · February 5, 2004

Hey guys I usually post here about AVALANCHE questions. However, my friends 99 Tahoe just seized due to low coolant. I notice that there was a TSB for low coolant on the 99 Tahoes. NO idiot lights ever came up on the dash indicating low coolant. In fact they wouldn't have noticed the problem unless the heater hadn't stopped working due to lack of coolant to the heater core. So when he took his truck into AMOCO they topped it off with coolant and his heater worked again. Then the next day the engine started running rougher and rougher until he finally took it back to Amoco. Amoco said it sounded real bad and told him to take it to the Chevy dealership. The dealership analyzed the oil and informed him coolant had spilled into the oil contaminating it. They must have dropped the pan because they also reported show main bearings. His warranty is expired. I told him to go ahead and call GM Customer Asstinance and open up a case. I told him to argue that at a minimum a LOW COOLANT light should have come up on the dashboard. They are in the process of deciding wheter or not to help pay for some of the costs. My question to you guys is this. Is there a known problem with low or loss of engine coolant in the 99 Tahoes? Any info would be greatly appreciated so that he can further build his case with GM

Thanks guys!

Frank S · February 5, 2004

My wife's '99 never had any coolant loss problems and what you are describing could be the result of several things including a blown head gasket,cracked head or cracked block.Anything like this can cause a coolant leak to the crank case but coolant isn't just going to end up in with the oil for no good reason.There had to be a major mechanical failure that caused the water/coolant to mix with the oil.

The Vortec 350's that were put in the Tahoes were the same as those in Silverados and were pretty good engines.I've not heard of any abnormal coolant loss from any of those engines.

intruder217 · February 5, 2004

Is there a "low coolant" light on the 99's?

Frank S · February 5, 2004

I don't believe so but if there was,I never noticed because ours never went low.

silverado4800 · February 5, 2004

Is a 99 tahoe the new body style? if so it should have the message center which which light up orange saying low coolant. Working on my truck, even if i lose a small amount it will come on, definitely on a hill or incline.

01Burb · February 5, 2004

Unless the low coolant caused an overheating which would have been indicated on the temperature gauge, I think your friend's Tahoe had some other failure.

Head gasket would have been evidenced by smoky exhaust.

A catastrophic seizure due to any number of reasons could have cracked a waterway allowing the oil and coolant to mix AFTER the fact.

Not much help...just my $0.02

MCourson · February 6, 2004

Is a 99 tahoe the new body style? if so it should have the message center which which light up orange saying low coolant. Working on my truck, even if i lose a small amount it will come on, definitely on a hill or incline.

99 Hoes are OBS and I think the only light that would have come on is the Check Guages light if the engine overheated.

SnakeEyeSS · February 6, 2004

yeah, there would have been many signs to warns about low enough coolant to freeze an engine. Maybe smoke, enough heat to notcie, and bad smells too.

saubouin · February 9, 2004

Well we called the GM customer rep dept to discuss having them help defer some of the costs to get the engine fixed. They aren't making any promises but have suggested they might pay for the new engine and my friend pay for the labor. An Exxon mechanic who also had a 99 chevy pickup said his 350 also seized due to a known intake manifold leak problem GM has known about but refuses to admit/recall/fix. Somebody explain to me how an intake manifold leak could cause an engine to seize?! The chevy mechanic is tearing apart the engine today and we should find out if GM is going to pickup any of the costs.

-HIC- · February 10, 2004

I have had 2 Vortec 350's (97 & 98) both of them started leaking coolant from the intake around 60,000 miles. Both of my leaks came from the front of the engine right hand side where the intake meets the head, and both leaked outside the engine. I guess I have been lucky that they did not start leaking on the inside directly into the lifter valley. I have talked to several other Vortec owners who report the same problem usually around 50-80k miles. As far as warning signs my Vortecs could run completely out of coolant and not overheat unless sitting in traffic on a hot day, and then the temp would rise I assume the check gauges light would come on if the temp rose high enough. I do believe the intake gaskets on the 5.7 have known issues that GM has not admitted, I do not however believe they are responsible for an engine that is out of warranty. <br>

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Now for my rant:

On the other hand I would think you would see some kind of oil pressure drop / erratic gauge readings with that much coolant in the oil. If my radiator was bone dry to the point no coolant was even getting to the heater core and there was no external signs of coolant leak I would sure investigate to find out where the hell it went.

Bryan

saubouin · February 10, 2004

Originally posted by HIC

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I do believe the intake gaskets on the 5.7 have known issues that GM has not admitted, I do not however believe they are responsible for an engine that is out of warranty.

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Bryan, I couldn't disagree with you more. I could care less if the truck is out of warranty. And I know GM cares because they frequently eat the cost on the new engine and let you pay labor. Here is the reason. GM knows that the person who has experienced such a catastrophic engine failure will probably never buy another GM vehicle. I also hang out on the Chevy Avalance Fan Club forum and one of our members has just lost his 5.3 motor with 50K. His engine is also out of warranty. GM is splitting the cost with him on a new motor.

jcathcart5 · March 4, 2004

I am having my 99 1500 v6 looked at right now. the low coolant light came on. I topped of antifreese looked for leaks none, no foam in oil, trans fluid good. does not overheat. looses coolant to below sensor and stops loss. pressure test good.

my mechanic whom i have used on my other chevys cannot find any leak anywhere. i only have 75000. i have let run 2hrs after filling no loss. i drive till warmed to normal operating temp and low coolant light comes on. i check its back down with no sign of leak.

i need help

john

NothinButBowTies · March 4, 2004

I am having my 99 1500 v6 looked at right now. the low coolant light came on. I topped of antifreese looked for leaks none, no foam in oil, trans fluid good. does not overheat. looses coolant to below sensor and stops loss. pressure test good.
my mechanic whom i have used on my other chevys cannot find any leak anywhere. i only have 75000. i have let run 2hrs after filling no loss. i drive till warmed to normal operating temp and low coolant light comes on. i check its back down with no sign of leak.

i need help

john

My 2000 4.3 did the exact same thing. 3 or 4 times a year I would have to put some in. The engine ran great at 110k when I traded it in with still no signs of a leak.

atomoverride · March 4, 2004

this thread is a real eye opener for getting that EXTENDED WARRENTY....100k sounds better than the 36k I am going to make sure I get it.

dtl66 · March 4, 2004

Just a side note. The truck I just traded was a 95 pre-vortec 350 and it also developed a coolant leak between the mainfold and the head(front intake runner LH side). A little stop leak slowed it down to tolerable for a year or so until I traded.