First of all I will tell you all now that I am no master mechanic. But I certainly can hold my own from time to time.

I recently bought (For the second time) a 95 Neon Sport DOHC from my ex. (Yes I paid for the car twice, once for her then again from her)

She claimed it was running fine but overheating. Her husband started to tear into it claiming that the water pump was leaking a great deal. He had the mount out the front timing cover etc... So I grabbed it up cheap and dragged it home on the trailer.

I tore into it and found a very bad water pump indeed... I decided to change the head gasket, timing belt, tensioners, plugs wires etc... After getting the head off I found zero evidence of a leaking head gasket. Cleaned things up as I normaly would and through it all back together. When I first fired it up I noted that it was smoking like none other and even had a slight miss to it. First thing I noticed was a vacuum leak where the old PCV hose was hard and broke at the PCV Valve. I sort of placed it where it needed to be which stopped the leak and smoothed out the engine. By this point I note the engine was overheating. I shut it down...

Then I pulled the thermostat with hopes it was not opening. No change, still overheating. Also I noted the fans did not seem to kick on properly.

Now I did run an oil additive that always seems to cause smoke for a short period of time but overall always madea difference. Pissed off I left the car alone for three days thinking the head was cracked.

Today I fire it up and let it idle. Temp climbing to below the half way mark and just sat there. I drove it around the block a few times and the temp started to climb up higher and higher. From the time I fired it up this time until this point I had no smoke, just light white smoke puffs when I would throttle it up a short bit to like 2k rpm.

After it over heated I noticed a lingering white smoke (Not a lot but enough to notice) and still no fan kick on. I turned the ac on and the fans kicked in, yet it did not cool down. Again i shut it down.

So from this point, where should I check? It may very well have a cracked head as I did not have it checked. Should I run a hot wire to the fan to see it possibly there is a bad relay/temp sending unit? I already know the water pump is cranking antifreeze through just fine.

I have 175ish lbs compression in each cylinder.

I just don't want to yank that head back off if there is another possible problem that should be checked for.


Any advice would be great.

And, sorry for the book lol.

 

Idcheck the coolent temp sensor. By the way you described it the rad fans turn on when they want to witch means the coolent temp sensor might be bad.

 

Are you sure you put the HG on correctly? I have to ask because I have heard it happen before. I know you said the head wasn't cracked, but it could have warped if your EX ran it while it was overheating.

 

Yep it's on right. After making a dumba** move once and putting one onwrong I always pay close attention to that.

Yeah the head could be warped. Or even cracked somewhere I could or did not see. I ran a hot wire to the fans this morning and still got it to over heat. Was hoping for a bad switch or something. Never that easy...

Just all seems weird. When ever I have encountered a head problem I have almost always had rough idle at the least. This thing is smooth.

Also in the first post I mentioned how it smoked really bad on first start up then a few days later it was not smoking. Well it had a small amount of white smoke... Today after it overheated before I shut it down I had some good amount of white smoke again.

At this point would it be best to yank the head off and send it down to be checked?

Thus far we have checked Water pump, Fans (By hot wiring them), Coolent system (Flushed it), and thermostat. I can't think of anything else at this point.

Again any advice is welcome.

PS. Also a stiff whip to the back for motivation would be helpful.

 

Thats what I would suggest.

 

One other thing.

The stock exhaust manafold has a nice stress crack in it now. I had planed on a header and exhaust system in the near future but if I am taking it back off I might as well do that now.

Where is the best place to start looking and what brands do you neon guru's reccomend.

 

If you don't have emissions testing get a long tube header.

 

Pressure test your cooling system with the engine off. Pump it up to 16 lbs. and let it sit for about 10min. watch the gauge and see if the pressure drops. if the pressure drops significantly, start the vehicle up and see if you have a misfire. If it misses, try to narrow it down to which cyl. either by pulling plug wires or injector harness.This will not only tell you that it is the head gasket but a specific cyl.

 

just because you don't see a crack does not mean it is not cracked

 

Yep Yep Yep...

I think I was more praying that it wasn't.

Got the head yanked off and in the shop. I see what seems to be a crack in an exhaust port now. No matter though, grabbed one at a junk yard in Kansas City today. Matter of fact I grabbed the entire motor from a wrecked 95 DOHC MTX Neon as well as the transmission and several other parts, including a TB from a SOHC 2.0 (Somewhere I thought I read that it was bigger then the DOHC MTX TB.) Spent a whopping 350.00. Gotta love those you pull it places that have huge sales like on the 4th of July.

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