Coolant Leak Question

My '99 1500 leaks about 1 quart of coolant on my driveway every 6 weeks. When I got under the rig I noticed that is is leaking out of the engine in two places.

Any suggestions on what I should do? Is there some sort of additive that I could use stop up the leakage? If I take this to a dealer am I going to get an outrageous charge or are fixes for leakage problems relatively simple?

Any help would be greatly appreciated. :smile:

First I would stongly advise against using any "stop leak" additives, because you will only regret it sooner or later. And second where are the leaks?

I'll give you a non-automobile-expert idea of what I see under there...

The leaks are both near the rear of the engine. One is on the rear passenger side, and one is at the corner of the very rear end of the main part of the engine. They appear to be comming from under a lip where the metals folds over. That "lip" is is about 3 inches below the block that houses the valves/pistons. The leak seems like it's coming from a logical place - where the engine appears bolted together, top and bottom. It as though some kind of seal between the top/bottom is leaking. I can see the pink dexcool dripping out after I park the car. However, it seems random whether is will leak or not after each ride. It certainly doesn't do it every time I drive the car. That is a crappy explanation, I know.

It sounds like it leaking from the head gasket.How many miles are on it. Being a mechanic I would say get it fixed as soon as possible, of course for me it would only cost me the cost of the gasket set. But realisticly that small amount ....it might be ok for a while but then again...(dont think I'm trying to scare you) it ,(if it is the head gaskets leaking)could progress to the point of blowing the head gasket, getting water in your oil, and a whole list of other possabilities. But first I'd try to find a reputable mechanic or bite the bullet and take it to a dealer, to get a positive id on where the leak is coming from.

if the coolant is coming from the back of the engine dripping down from the starter it is the gasket that is between the manifoil and the engine this gasket will cost around 25.00 - 56.00 if you take it to a dealer they will charge between 400.00-575.00 to repair any other shop will charge less. It will take about half a day to repair,the carb and everthing under will have to come out. have it repaired as soon as possible ,the good news is that these gasket can burst either way to the outside or inside since it broke to the outside no damage was done to the engine,when they rupture to the inside the coolant leaks into the oil and 95% of the time the owner doesnt know till its to late and the engine needs to be replaced cost 3500.00 hope this will help

Thanks for all the advise.

The problem --> It was diagnosed by a shop as a "coolant intake gasket" problem. Needs to be replaced OUCH! I received the following quotes:

Firestone Services Center - $814
Goodyear Service Center - $640
Chevy Dealer - $750

I then played Firestone off against Goodyear and they matched the $640 quote.

Join the club... that is a common problem with Suburbans (1999)

I just replaced mine and the dealr said i was lucky to make it to 120k miles.....


runningjalapeno is right, get this fixed ASAP.. a $450 problem could multiply into a $3500 problem.


i only paid 450.00 for parts and labor...
i would call around for better prices.. stay away from Firestone and goodyear places... try a trusted non franchised mechanic.

Bluephi,
I agree. I'm still looking for good non-brand name mechanic. I've always purchased new cars and sold them shortly after waranty expiration. I'm into the used car thing now, so that is an imperative.

Same thing with my 99 with 119k miles. Pep Boys replaced the gasket for $350...

Since I recently had the problem, and did the repair, there are a couple of
points that are important.

The intake maniflold gasket leak apparently happens to every 350 vortek
out there. And no wonder. GM made a major design mistake (or three).
The intake is aluminum, which is difficult under the best of circumstances.

In their quest to do it cheaply, GM decided to use a plastic plenum to
house the fuel injectors, which are centrally located in _the manifold_
instead of along the heads like other manufacturers. This plastic "top"
weakens the manifold structure further (temperature stability is decreased).

Then the coup de gras: they use FOUR bolts on each side of the manifold
to hold it to the heads. Two near the front, and two near the back. A long stretch of unstable aluminum is in between. As a reference, six or eight bolts on each side were used on the older cast iron maniflolds. To TOP IT OFF they torque these new units to 20 foot-pounds. TWENTY!
AND use a real thick gasket to try and compensate for their corner cutting.
This CAN NOT last, and anyone who looks can see why.

This was one of the most tedious jobs I have done in recent memory.
The underhood layout was unbelievably bad. Every thing attached to
some bracket or bolt, wiring harness like an octopus instead of neatly
laid out. ETC. A major example of how to screw your customers.

In my not so humble opinion, GM has gone bean-counting and makes
every part of every vehicle to a price. It only need last 3 years/
60K miles for the lease. After that you had better have sold it.

Mine lasted 60K miles. It will fail regularly on all of these vehicles.

Yes, I'm mad.