I took my truck to auto repair shop because it was overheating. The machanic replaced the water pump, thermostat and fan clutch. I took it for a test drive and it still overheated and the oil pressure light came on. I took my truck back to the mechanic and he replaced the oil pump. After putting in the new oil pump he said I had a blown head gasket and a hole in one the pistons. So I told him to replace the engine. It was running great but while on my way to California I noticed the temperature gauge was maxed out. I pulled off the freeway and checked the radiator but it did not need water. The engine was not knocking before I pulled over so my truck started okay. So I just thought the temperature gauge was faulty and kept driving. After awhile my truck started knocking. I took it back to shop and the owner told me he fixed it but my truck still overheats. What can cause a new long block with a new thermastat, water pump and fan clutch to overheat?

 

Maybe it's not overheating at all and instead it's just a bad temp gauge sending unit or the gauge itself? Using an infrared thermometer, point the instrument at the water discharge on the engine when the thing seems to be overheating and take a *real* temperature reading. It could also be a collapsing lower radiator hose or a radiator that needs a good flush.

*Is is boiling over?
*What are you driving? I'm lousy at guessing .

**Your mechanic seems very eager to jump into repairs that from what you've said are generally not all needed but are costing you money. For example, he puts in a new oil pump (I wonder how he made that conclusion) on an engine that needed a new head gasket and had a hole in a piston? That's just plain crazy. Also, why put a new thermostat and water pump on an engine with the noted problems? That would be wasted labor. If there was a hole in a piston, it sure must have ran real rough at all engine speeds and conditions. Beware of this mechanic.

 

It's a 1988 Ford Ranger with a 2.9 Liter engine. When I first went to the repair shop my truck was leaking water. The water pump was leaking. After replacing the water pump, thermostat and fan clutch the truck ran good. When I test drove the truck on the freeway my oil pressure light came on and the engine overheated and started knocking. So I took it back to the shop and the mechanic replaced the oil pump and the engine still over heated. This time he pulled the heads and found a blown gasket and hole in one of the pistons. I told him to install a new long block and everthing worked well for a few days. Then one day while driving I noticed the temperature gauge was reading hot and pulled over to check the radiator. It was not booling over so I thought the temperature gauge was bad. But the truck started with no problem so I drove about 20 more miles and stopped to check it again. This time the reservoir tank was booling over. I let engine cool and the engine started okay. So I drove another 30 miles and the engine started knocking. I made it to the nearest town and purchased a new truck. This was on 9/28/05. The next day I towed my ranger back home and took it to the repair shop that monday. I finally got my truck back yesterday and today it overheated again. The long block had less than 140 miles and still under warranty. Today the mechanic said he ordered a new engine and should have my truck ready by Wednesday. Will see. But I am still wondering what can make a new engine overheat. They cleaned the radiator. The mechanic kept telling me it was one of the spark plugs. Yeh right!

 

Yeah something's up with this mech. A spark plug isn't going to overheat a brand new engine. Obviously something is up with your cooling system.
You say you had a new long block installed, did you have a new capable radiator installed as well? The stock radiator may not be functional enough for the new engine. Might not hold enough fluid.
Is it holding fluid? And are you positive the cooling system is hooked up right.
Something is up with this mechanic, I don't like the way he suggests all this stuff and produces no real results.

 

I replaced the OEM plastic radiator with a larger Modine radiator. I am thinking air trapped in the cooling system after replacing the long block caused the engine to overheat. This is what I told the mechanic who kept insisting it was a spark plug. According to the mechanic the engine manufacturer did not want to replace the engine so he tried to repair it by replacing the head gaskets. After replacing the head gaskets the radiator was loosing water.

 

Hmm...this guy doesn't strike me as really...ahh what's the word, I lost it...experienced sounds good.
Well you fill the radiator and drive. The system begins to purge itself and the level of fluid goes down, which is perfectly normal. Do you have enough fluid?

 

First things first, FIND A NEW MECHANIC. a mechanic that can actually fix the problem without screwing around costing you more money to fix a nonexistant problem.

This guy sounds like he merely wants money, and lots of it. your problem is someting not letting the coolant flow properly, and it NEEDS to be flushed out good, then you might see an improvment or two.

 

Generally: A bad radiator will cause overheating while cruising down the road.
A bad pump will cause overheating while the engine is at idle.

Take your pick.

But. This mechanic doesn't seem to be firing on all cylinders, so to speak. The 2.9 is noted for eating cam bearings thus leading to low oil pressure. A new oil pump will not fix low oil pressure in MOST cases. It is a band-aid for a major problem, and most times will not have any real effect. The 2.9 is also known to crack the cylinder heads.
The re-man engine should have a warranty. They should cover the cost of the tow from where it broke. They should cover ANY labor cost to replace the defective engine, and probably the cost for new oil and filter. A good company stands behind their product at least for 90/6000 if you ask me.
tom

 

I agree with everyone else that you mechanic should should go back to stripping cars at the junk yard. I have to ask, How much money have you given this slimy guy to "fix your truck"??? I would have done the same thing as you and bought a new truck also. Sometimes new engines will run hot while they break in due to the tight tolerances but thats only at idle. I would suspect that since it's when it's going down the road and the mechanic is sure theres no problem with his "mechanic skills", then i would make sure there is no debris on the condensor or front of the radiator since that will cause overheating at any speed. You can also try running it without the thermostat and so what the result is with that.

 

Since the 2.9 is well known for cracking cylinder heads due to overheating (and it can happen on just one occurance of overheating) it would be nice to determine of that's the problem. Any oder of exhaust in the coolant? Any steam in the exhaust? Does the oil look like a chocolate milk shake?

*It's hard to believe this guy thinks "one of the spark plugs" can cause it to overheat .