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Stop the bleeding

I have a 98 chevy suburban - it currently has 209,000 miles on it and until recently was running without problems. It started leaking coolant. I brought it to a mechanic and he said it was the R&R intake manifold so he replaced that along with replacing gaskets with updated style. That was a $450 job. I took it home, it didn’t stop leaking coolant, it was back in less than two weeks later and he said the problem now is the water pump. He replaced that at $350. It is still leaking coolant, much slower leak but still dripping. He asked me if I had the radiator replaced. I told him I hadn’t that I recall. he said the leak is between the plastic shield and the metal part of the radiator. I did go thru old receipts and had my water pump replaced a few years ago at a much lower price of $94…so my question is, does it make sense that these repairs have been made and it is still leaking? Does all or any of this seems reasonable?

is this your regular mechanic? next time I think I would get a second opion and go from there. sounds like he is just doing part replacement and not troubleshooting the problem, these are all none problems with your truck

At 200K anything is possible but first thing I do if I have a leak is crawl around underneath trying to figure where it is coming from. Before I’d spring for the radiator, I’d want to make sure the other components such as the hoses, pump, etc. aren’t still leaking. Might be time to have someone else look at it first.


I agree that this guy is not doing right by you

I’m well aware that the intake gaskets commonly fail on these older GM V8 engines

Let’s say the intake gaskets were actually leaking . . . fine, but I suspect that the water pump was already visibly crusty when the guy did the intake job

When you replace the water pump on these engines, you have to scrape off the old crud on the block before installing the new water pump and gaskets. I wonder if he used some kind of power tool and removed too much material. If so, you’ll have a devil of a time killing that leak

As for the radiator . . . I wouldn’t be surprised if the radiator tank already was wet when he worked on the truck.

When working on a cooling system, you have to make sure you’ve found all the leaks before preparing an estimate for the customer. It sounds like this guy didn’t look very closely.

Why don’t you crawl underneath the truck yourself and see what’s leaking?

to diagnose a mystery leak, Someone needs to CLEAN first.
Clean and dry, clean.
The engine and radiator. leaks get on many other surfaces and become a big mess. leaks drip and run down way from their source.

Then as the leak begins anew…

But watch out - I’ve sold a radiator to a job that had merely a hairline spray from a hose end.
The spray was difficult to see and what they saw first was the drip down from its target on the radiator.

PLUS , with cooling sytem leaks, it IS a very real possibility to find new leaks as the system pressures up to bust the next weakest point that wasn’t leaking before…( been there, done that ) especially on an older vehicle.

This guy might not be doing right by you, but on a car that old, fixing one leak could cause another, so it’s hard to say that for sure.

Has your mechanic pressure tested the cooling system, or is he just throwing parts at the problem?

Does this vehicle still have any of the original hoses? If so, I would have replaced them by now as maintenance.

In addition to having the whole system pressure tested, you might consider having the radiator flow tested if it isn’t already leaking.

"does it make sense that these repairs have been made and it is still leaking?"
It does to the mechanic who maybe making college tuition payments.

“…does it make sense that these repairs have been made and it is still leaking?”

It does if the cooling system has multiple weak spots and fixing one leak increases pressure on another weak spot. I need to know more about this truck, like how well it’s been maintained, how often the coolant has been changed, how rusty and corroded the engine and seals are, etc.

It is still possible all these leaks could have happened at the same time with a 200K engine. Especially if the coolant hasn’t been changed out per the recommended maintenance interval for the cooling system. Also, it’s possible you have a head gasket problem that could be contributing, might be worth it to have that tested. And check the PCV system while you are at it, when that fails it puts pressures on the engine gaskets. A PCV failure usually causes oil leaks, not coolant leaks, but it is easy enough to check.

Radiator leaks where the plastic part meets the metal part are pretty common. I had that happen w/my Corolla a couple years ago. I replaced the radiator, but radiator shops are often able to repair the original radiator too. That might be a better option if you have a big cooling load, like if you live in a hot area, routinely drive up a lot of steep long hills, pull a trailer, a lot of low speed idling, have an automatic transmission, and AC. If you have none of those, an aftermarket radiator would probably work ok. Mine cost $89 and took about 30 minutes to install.

As mentioned above the first thing for this kind of problem is to determine for certain where the leaks are originating, before replacing stuff. I think there is a dye kit you can purchase at auto parts stores that you put the dye in the coolant, then after a few days you inspect the engine with a special lamp that comes with the kit. Makes it easier to see where the leak is originating.

Replacing the coolant with new and changing the thermostat to a new one should probably be done as part of this project.

I seriously doubt of this guy is doing due diligence to try to determine the source of the leak. He’s just throwing parts at the car at your expense.

IMHO the next thing you should change is your mechanic.

Just curious, did you recently have the cooling system flushed, did you use a chemical flush agent in the cooling system?

It’s the finger in the dike story.

You see a leak in the dike and you stick your finger in it. Then another leak appears and you stick a finger in that one. Then another appears…

It’s just cooling system showing where the weak areas are as you start plugging up all the leaks.


Thank you for all of your suggestions…I do take very good care of my truck, but I don’t think of everything, like having the coolant system flushed. I don’t know when that was done last. I am taking the very good suggestion of bringing it to another mechanic for a second opinion, my original mechanic actually. The radiator work was done by a “substitute” because I was temporarily out of state and it needed to be looked at, it was originally leaking coolant really quickly…my original mechanic should also be able to tell me if the radiator has been replaced before, as suggested by the substitute mechanic.