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Help please! Shop replaced leaky radiator, < 2 weeks later, replaced thermostat, now engine fried

Hi. Would love some advice. I have a 2002 Honda Accord. 135k, a fabulous car. Until recently. At beginning of May had a LOT of work done in connections with the check engine light, for it to pass emissions so I could renew plates. Yada yada yada. Sorry I don’t remember all the exact things, nor do I have the receipt in front of me.

But three weeks ago, I took back into shop due to a coolant leak. Shop replaced the radiator.

One week ago, engine was overheating (stop and go on a long bridge), and shop replaced the thermostat.

A day later, car barely started, and then check engine light flashing, and ROUGH is not the word for how it ran, died without foot on gas pedal. So - they say there is coolant in one of the cylinders, because the head gasket is blown.

As far as I’m concerned, the car is done for, but what I’m wondering - how upset should I be that apparently the shop did not check the thermostat at the time of the radiator repair? If they had - I might still have a car right now? Yes?

You kept driving it in the stop and go traffic on the bridge after the gauge went to hot?

If so, it’s your fault, and only your fault. You took it in to have a leaking radiator fixed. The thermostat is not in the radiator, and the shop likely does not want to deal with customers being mad that they checked various parts that aren’t involved with the repair on the off chance that they might be bad. And that is understandable. If I take my car in to have the fuel filter replaced, I don’t want them charging me to diagnose the fuel pump just because both parts happen to deal with gas.

On the flip side, when the needle heads toward hot, it means pull over NOW and shut it down. If you can’t pull over because it’s a long bridge, then that’s what the hazard flashers are for. It was stop and go, so you weren’t going to get slammed into. Turn the car off, turn on the hazards, and wait for it to cool down.

With all what shadow said being true, if the car was fine in moving traffic and only started overheating when in stop go traffic… MY thought would be your cooling fans not clicking on, NOT the t-stat… Usually if the t-stat is stuck closed, it will overheat all of the time and very quickly in this weather. IF they did not plug in the cooling fans after the radiator, they MAY bear some responcibility for the damage.

At some point is seemed the motor overheated. Perhaps when the radiator was bad and losing coolant the car overheated? Then you reported overheating due to the thermostat.

Honda uses a lot of aluminum and some exotic metals in the heads and block and they simply don’t handle overheating. The metals expand at different rates and the seal of the head gasket is breached.

Some of these overheated motors are repaired by replacing the head gasket, others have more significant issues such as a warped head which means more money.

I think you need a new shop.

The very real possibility exists here that the headgasket leak has been the root cause of your overheating from “day one” and the shop changed the radiator and then the T-stat without ever doing the proper diagnosis. A headgasket leak would cause “cooolant leaking” because it would not only heat up the coolant in the water jacket, but also blow it out the reservoir overflow tube. It forces combustion gases into the water jacket, which push fluid out the radiator…which causes it to overfill the reservoir.

The reason I say that is because they don’t appear to have done any real analysis, just changed parts. If they had done good analysis, they would have started with a cooling system pressure test. If the pressure test did not cause coolant to push into a cylinder (very possible), they would have been unable to confirm a system leak and would have looked further. If the system did lose pressure, they would have had to evaluate where it went and discovered the headgasket problem.

Even if the old radiator did actually leak, in testing the system after installing the new one they likely would have caught the headgasket leak.

I’m hearing things that make me suspect they didn;t do the diagnosis part very well.

By the way, just because the headgasket blew does not mean the car’s history unless there’s damage that you haven’t mentioned, like you were on the highway when it happened and you crashed the valves into the pistons and did bunches of damage.

There’s not enough detail known for me to hazard much of a guess. Things like wondering what this plethora of repairs were that led to failed inspection (emphasis on your use of the word LOT), whether there was any overheating before the radiator replacement, whether the T-stat was a legit diagnosis, and how severe along with how long this bridge overheating went on, etc. are just some of the unknowns.

A T-stat can be a hit and miss thing. Some fail and stay failed, others may be failing intermittently. The fact that a week went by between the radiator and the T-stat failure could mean an intermittent failure in which any check of the T-stat would have been meaningless or it could mean the entire diagnosis was wrong from the get-go. There’s just no way of knowing for sure.

Bravo to Mountainbike… I did not even think about it, but he is 100% right… It is at least possible your head gasket was bad the whole time and the mech was just throwing parts at it.

Mountainbikes scenario is very likely how the story played out but there is no way to know at this point. And, it is sometimes quite difficult to diagnose a failing head gasket with any certainty. Many may laugh but I learned to smell the overflow bottle for the telltale odor from exhaust mixed with coolant and my nose was more accurate than the chemical test or a CO detector because they only detect leaks that are occurring while testing and head gaskets often leak when the engine is hot and loaded while they don’t leak when cruising and relatively cool. Aluminum will warp when it is overheated and when it cools it will set to the warp and if (when) it overheats again it will add to that warp and the warp weakens the seal of the head gasket at the widening gap. In recent years this man’s story has shown up at my door a few times and I have recommended repairing whatever immediate damage is present, replacing the thermostat and boring a weep hole in the new one and adding one of the block sealers. Some of the cars didn’t last a month but quite a few lasted until some other expensive part failed. It’s a crap shoot but it paid off often enough for me to recommend it.

I concur w/Mountainbike that the problem was probably the head gasket to begin with. A faulty head gasket often will cause the radiator to spring a leak. Can’t know for certain of course. I guess you could complain the shop should have tested for this. But they probably figured with 135K on a 2002 it’s not unusual for a radiator to just give up the ghost, and you want the car back on the road, and replacing a radiator isn’t usually very time consuming and not that expensive.

I’m not sure if it is common for a shop to test the head gasket when a customer comes in with a leaky radiator and no other symptoms. Anybody know?

It isn’t but it is common pratice to notice scummy coolant and look a bit deeper.
As others have stated, there’s really no way to know, but this one just gave me a bad feeling. It is possible that these things were all about to happen in the order they were diagnosed. But it sounds shakey to me.

There is one more possibility, the thermostat controlled fan quit working and if so, it may still be bad. If you still have access to the car, turn the ignition to the on position, turn on the ac and see if both fans are operating. If one isn’t, it could be the root cause of the whole problem. Still bad troubleshooting though.

Yes, @Keith is right. Any time a car overheats, the first thing to check is if the radiator fan is spinning. If it isn’t, at least you know one thing for certain that needs repair.

If the radiator fan isn’t spinning, sometimes you can get enough cooling to get you home by turning on the heater to full hot and the (passenger compartment) blower fan to Max. It’s a good idea to do that anyway if the car is overheating, even if the cause isn’t the radiator fan. The heater provides a surprising amount of engine cooling in a pinch.

Usually a non-spinning radiator fan is caused by the coolant temperature switch rather than the fan itself. Replacing the temp switch is simple and inexpensive on most econoboxes.