My car started overheating slightly so I went through the protocol. Changed the thermostat and checked for leaks. Filled with fund and vented the air from the system. Then the damn fan stopped turning on. Changed the fan switch. Still overheating. Checked for signs of a water pump or head gasket issue. None. Took it to a shop I trust. They told me that the d16y8 sometimes needs to be raised on the front end to properly purge the air out of the system and that it was an air pocket in my water lines that was causing the overheating problem. They also informed me that this was the reason the fan switch was not calling because there was not sufficient water passing through to call the fan switch. Sounded believable enough and it was an inexpensive fix so I went with it. Car started overheating again today and the fan switch did not call. Keep in mind I can dummy wire the fan so I know the fan motor is working and that the electricity going to the fan is working. I then let the car cool down open the radiator cap started it purchase it and seemed as if I needed some water. I squeezed a couple of the radiator hoses and they were empty so I kind of squeezed on them until they filled up with water. Drove home and the fan never kicked on but the car did not overheat. My oil looks good and I have no smoke coming out of my tailpipe. There are no co2 bubbles coming out of my radiator cap. I don't have any radiator fluid dripping on the ground at least while idling or parked and I don't see any leaks around the area of the water pump. Has anyone had any experience with an issue like this that may have an idea of what the problem is before I take it back to another mechanic?

 

If you don't have overheating issues and only have a fan operation problem than you can test the fan switch to see if it is working as it should.

 

It's overheating. Yesterday in traffic it started overheating and then it blew the heater core hose off as u was pulling it off the road. I walked to O'Reilly's, got fluid, hose, and clamps. I refilled the system and dummy wired the fan again. It drove home on the highway just fine. It's in the shop again. Maybe the water pump is failing at idle and low rpm's. Not sure. I'm going to order a new radiator(which I was gonna do anyway for turbo fitment reasons). Also going with an oem fan. This aftermarket one that came on the car doesn't put enough air out.

But I'm still clueless as to what the problem is. And I hope it's not the water pump.

 

When you swap the motor in did you bother to replace the timing components, including water pump and seals in that area?

 

I bought the motor swaps and it was a complete bottom up rebuild but I did not ask the guy if you put a new water pump in. The rebuild is done really well and I've had no problems with the motor so I'm guessing that he probably had sense enough to do that. I actually didn't even have any overheating problems until I've developed a small leak and the system bled down a little and I replaced the thermostat and fan switch and I've had nothing but problems since. Of course I'm also keeping in mind that we didn't have a very hot summer and only over the course of the last 3 weeks has it gotten really hot enough to affect the car. So to answer your question I honestly don't know if he replaced the water pump but I know it has a new timing belt and it's time to properly.

 

How can you say it had no problems when you're having one now......

 

Because I drove it for 3 months before the leak developed. It never overheated once. I guess I should say that to my knowledge it did not have a problem but perhaps there was a problem I was unaware of.

 

I did but haven't gotten an answer back yet.

I thought head gasket as a possibility. The oil is clean. No smoke out the exhaust. No CO2 venting out the radiator when I open the cap and idle it. But if it hasn't blown the head gasket yet would I see any of those things?

 

Did you ever find the problem to the overheating?

 

Yep. It was a temp spike because the 20 over bore and all the mods. I put a gates racing thermostat on it and solved the problem. Crazy the amount of time and money I spent to find the problem.

 

That literally makes no sense.

 

If I had a better explanation I'd be happy to give it. I had a vacuum test done. I replaced the radiator and fan, hoses, thermostat housing. Didn't stop the spiking. Someone suggested that I try a thermostat that opens at a cooler temp. I ordered a gates and put it in. No longer had the problem. True story. I wish I could make more sense of it because I really struggled to fix it and it's my daily.

 

And it occurs to me that you never offered up any information that did make any sense. That's an old thread and the problem has been solved for quite some time now. But thank you for being so helpful.

 

Your "racing thermostat" fix didn't actually fix anything, it just put a bandaid over the issue that you still don't know the source of. "20 over bore and all the mods" doesn't even give enough information for anyone to try to tell you what's wrong, and we're only just now hearing about it? That's not how things work around here. Actually, your entire thread is a huge example of "not how things work around here". Posting about a 91, in the 92-00 section. Not giving full details. I'm surprised a mod didn't call you out three months ago when this whole fiasco started.