Cooling issue

[wmdpalmer]

I just purchased a 94 Ex Limited. 108K miles. The Temp guage would barely move after warmup. I changed the Temp sensor and it wouldn't move at all. I returned that part and out back the original and then put in a new temp sending unit. still no movement on the guage. I went to Checkers and did the Trouble code scan. came up with code 186 and 181. I purhased a new thermostat to put in this weekend. any ideas if this will fix it. Car runs fine, idles good, has heat. Any ideas???

 

[Howard]

Sounds very like the thermostat is stuck open. New one should fix it. Very common failure.

 

[MrShorty]

New thermostat should fix the not warming up issue.
The codes 181 and 186 are mixture related. PCM has seen (or thinks it's seen) the engine running too lean, and couldn't compensate. Clear the codes after you replace the thermostat and see if the trouble codes come back. If you don't want to take it to Checker everytime you want to check the codes, you can check the codes yourself with only a short piece of wire (paper clip has been known to work for this). Trouble codes will show up as flashes of the CEL. See www.dalidesign.com/hbook/eectest.html for instructions.

 

[wmdpalmer]

Thank you for your replies. I will let you know my status after the Thermostat!

Will

 

[wmdpalmer]

About how does it take to change the Thermostat on an Ex? Any useful tips/helpful ideas??? Thanks!

Will

 

[MrShorty]

One the 4.0 OHV, I've always prefered to remove the best tensioner pulley. Perhaps not necessary, but it makes getting at the thermostat housing a lot easier.

 

[wmdpalmer]

Well good news! I changed the Thermostat and it works! I have to get an air bubble out it seems though. Thanks for the assistance!