Running Hot

kvnhpnr · 03-19-2010, 03:32 PM

I replaced the water pump on my 86 944 less than 6 months ago and recently I had repair various other engine components...I took the top 1/2 of the cover off to make sure the water pump was spinning, it was. The hoses are not bound or clogged...what could this be?

SolReaver · 03-19-2010, 04:53 PM

Hmmm. Something similar happened to me. It turned out to be a bad thermostat.

Was it running hot BEFORE you did the WP....AND...did you replace the thermo with a new one? if so...where did you get it and what does the box look like? Could you test it with the "old thermo" (yea, it IS a PITA, I know I have done it)

How hot is it running? I mean, where on the temp gage does it settle in? Any other syptoms? When does the fan(s) kick in?

kvnhpnr · 03-20-2010, 06:43 AM

When I bought the car the water pump was shot and there was not even a thermostat in the water pump however there was one that was in the trunk in a box of extra parts (plugs, fluids, thermo, etc). The fan has also been bypassed and run off of an additional switch and tied into an additional aftermarket fan which they installed themselves, I will have to rewire and rerun all the wires for those since they were working before but now they are not. I will get the correct thermostat to see if that solves that problem.
Another problem I found was that the AC compressor power was being controlled by a 3 amp switch which would smoke when turned on, not sure if AC works, havent charged yet but I have to rewire that also.
ANY MORE SUGGESTIONS

SolReaver · 03-20-2010, 07:28 AM

Well, the good news is that the overheat is prob not something that you caused. The bad news is that it could be any one of several problems. Do a search on overheating in this forum and check with Clarks for a few more ideas.

There is a possibility the Thermo was (is) defective. As you will be putting in another one just to test, I suggest that first you make sure that the thermo you get is good. There appear to be a few bad ones out there. Secondly, as you are opening the coolant system anyway...take out the radiator and clean it as best you can. You have to put it on it's side and flush out the gunk. (they DO get gunky) A good way to test the radiator is to simply feel for cooler spots. When running and working, there should be none and the radiator should be uniformly warm. Also check the temperature of the upper and lower hoses.

Someone running without a thermo is a desperation move to try and bypass the problem without having to deal with it. As far as the smoking switch...Been there ...Done that. You can either wire a headlight relay and fuse in to handle the power or return the vehicle to the stock wiring, which, will likely be broken as the PO bypassed it. I would forget about the AC for now and concentrate on getting the car to run at the right temperature. One problem at a time.

Welcome to the asylum. Put your make model and year in your sig. Try to answer the questions given...How hot is it running? I mean, where on the temp gage does it settle in? Any other symptoms? When does the fan(s) kick in? does the temp fluctuate while driving? hotter on highway or sitting at lights. Get descriptive. It helps.

smokin_944 · smokin_944's Garage

+1 Sol! Year of car is important because series 1 cars (83-85/1 are setup differently.

SolReaver · 03-21-2010, 10:28 AM

Exactly. I can only answer in generalities and I am of course Most familiar with 87 924S. Others with the exact model MIGHT have a quick fix. (OK, maybe not) I mean, there are 3 diff temp fan switches, and several wiring options for the control circuits. As my crystal ball is out of batteries I can't really divine the exact solution.