This thing has been acting funny since the day we (read: my wife) bought it. First, it was overheating like CRAZY pretty much all the time. Would have to pull over and let it cool off. Replaced fan clutch, worked fine for a while. Started overheating again about a month or two later. Replaced fan clutch again AND water pump. Worked great for a little under 24 hours. Replaced the serp. belt because it was squeaky and just in case not enough torque was getting to the water pump due to a loose belt. Stopped the squeak, still overheats. (but not too bad unless you have the AC on... gets up to about 210 with no AC, redlines with AC.) Flushed radiator twice. No help. Replaced thermostat twice in 6 months. No help.

Finally took it to a dealership. Told me the compression test went badly, 40 lbs. low on two cylinders. Quoted me over $2000 to fix it, replace the head gasket and intake valve gaskets. Told them to give me the keys, drove it home. Not long after I got it home, now the idle is VERY rough. almost sounds like misfires. Rarely, the check engine light will come on and blink 8-10 times, then go off. At low RPMs, the truck sounds like it might die. Once you get going, it's still rough, but more consistent of a sound.

I never believe the dealership when they tell me anything is wrong with a head gasket. Too many times have I been told this and I replace a throttle position sensor or something equally as cheap and the problem is completely fixed.

Anyone have any thoughts? I'm just trying to make it to winter so I can drive it to the dealership without overheating to trade it in.

Thanks!

 

Does it overheat constantly or just in stop and go traffic and while parked? I would suggest taking it to a car wash and cleaning out the fins on the radiator and also check for damage om it and the a/c condenser. If that doesn't work out for you it may be that the radiator is actually plugged. It sounds like the previous owner didn't take care of the cooling system and it may just need a new radiator. The radiator has a check valve in it so you cannot do a reverse flush on it and a regular forward flush won't do much in the way of cleaning crud out of there. As for the idle I would definitely look into a new TPS like you were thinking.

 

Actually, it really only overheats under load. It will overheat if you sit there and idle long enough, but it really shoots up there when you're going up a nice hill. I wonder if there's any other way to check the radiator other than just a flush since that apparently won't work? For what it's worth, the water flowed out of the radiator very well when I did the flushes myself. Argh I hope the head gasket isn't really blown... I can replace that, but you know... An engine is never the same after you take the head off...

 

Well it may flow out ok but I imagine all it takes are a few lines being compleetely plugged and it can give you problems. The only thing I can think of is to get one of those IR thermometers and look for temp differences along the radiator. I think they are about $50 but would be well worth it if it helps.

 

This happened with my '01 SLT. Had to replace the radiator after going through similar troubleshooting. Same problem--flushed radiator, looked okay but still ran like crap. Took radiator out, could find a clog that would not budge; replaced radiator and temp problems are gone.

 

RB:

I would agree that the radiator is easier and cheaper to explore at this point especially due to your D's age. If the radiator does not cure it, I would do my own compression test and verify that the cylinders are low. If so, time for a gasket and valve job x 2. There is some history with the older 5.2/ 5.9 motors having head gasket failures.

Be careful though, if you continue to drive/overheat it you can damage the block and heads to the point that they are no longer serviceable.

Don