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2002 Grand Cherokee: head gasket vs. new motor? Desperate for objective advice!

Hey guys, I could use some objective advice. It’s a 2002 Grand Cherokee 4.7L, with 130K miles on it.

I had my Jeep’s radiator/hoses replaced over the summer, and have had a nagging issue where, about once a month, the upper radiator hose will slip off the neck and lose a bit of coolant. Had it back to the shop (Firestone) a couple of times and they did a flush, etc. but nothing helped. Took it back last week, and they said pressure is building up inside the cooling system and that’s what is blowing the hose off. They said they weren’t able to finish a block test as the coolant was overflowing into the test fluid or some such. Based on that, they think it’s either a cracked head gasket or (less likely) a cracked block.

The thing is, it’s never overheated or had any other issues; in fact, if the hose had stayed put, I’d never have known there was a problem. No loss of coolant (except when the hose slips off), no oil loss, no discolored oil, no overheating, no knocks, no vibrations, no power loss, no white smoke from the exhaust… nothing. I’ve had an eagle eye on the temp gauge since the radiator work was done, and it’s never budged past the 12 o’clock mark, even in the Houston summer in rush hour traffic. My father in law was the previous owner (bought it new) and never had cooling issues, either.

We’re taking it for a second opinion to an independent mechanic, and he was a bit wary that Firestone didn’t really track down the issue, and is going to run diagnostics on it later this afternoon. However, he said if it is a head gasket, they would never recommend just doing the heads/valves and would instead recommend putting in a new/remanufactured/rebuilt engine, due to possible damage to the lower parts of the engine.

Anyway, I’m at a loss. We definitely can’t afford a car payment right now, so getting the work done, be it heads/valves or a remanufactured motor are the only viable options. Any advice you can give me would be greatly appreciated.

Get another opinion and avoid FIrestone at all costs. My suspicion, right or wrong, is that this could be a hose fitment issue; meaning wrong hose or improperly fitting hose due to shoddy manufacturing.

If a cooling system is building up enough pressure to dislodge a hose then the cooling system pressure cap should release first; unless the cap is faulty.

I think that worrying over a head gasket or failed engine is a bit premature at this point.

I would get that second opinion first.
then if…
IF it’s a head gasket problem, consider a whole remanufatured engine.
if you intend on keeping the car for more than the next three years or longer.
Why ?
One thing is the warranty. So many remans now have a 36m unlimited mileage warranty ( or 36m/100k ) that you can’t possibly justify putting on a few parts that have no warranty.
The other this IS the additional un-repaired engine parts that all have that 130k on them . Just how much longer are THEY good for ? and do you want to chance it ?

@ok4450 I completely agree with everything ok4450 said.

The thing about the pressure issue is that they said during the block test the coolant was overflowing into the test fluid at the radiator neck, so they weren’t able to get an accurate result. I do recall they mentioned that they took out some coolant to give them more air space to work with and it still overflowed into the test.

The last time I walked into our local Firestone store, the manager turned pale. Apparently I was a dead ringer for the last inspector from the state Attorney Generals office that had come due to complaints. I had come to get a tire adjusted, no way I would go there for anything else.

Wow, just got a call from the second mechanic: it was the left motor mount that was bad. Block test was totally normal, everything else is good. Installing a mount and a longer spec upper radiator hose today, and it’s all good.

Lesson learned: Go to a real mechanic, because Firestone sucks.

@ok4450‌, you get a cookie for closest guess to the solution!

Thanks to everyone for your thoughts!

@Nostratic so glad you got your problem solved correctly and did not get shafted. Please put your new mechanic under the Mechanic Files link. This way others in your area can find them too.