Hello all,

Not a regular here by any means, but I've owned 2 maxs now. My newest max has just rolled 120k and is doing great. I just did the timing belt change for 120k, which included the thermo being replaced, and it appears I got a nice symptom as a result. See if this is a result of the thermo (keep in mind I'm rather incompotent when it comes to my max mechanically).

As I'm driving away from having my max worked on, my heater magically won't produce heat immediately... even on the hottest setting, it's shooting cold air. It was fine before. Then, in random intervals, it would shoot hot air as if all was fine, then shoot a little cold, then hot, repeat... However, last nights problem was worse. As I was driving home from work, at about the time the engine gets fully warmed and the temp needle usually sits just a tad below half, I saw my needle plummet to almost C, then rise all the way up to the H, sat for a minute, then dropped back down to the middle where it should be and was fine for the duration of my trip (I pulled over and looked under the hood when this happened as a precaution, but everything looked fine, and ran fine obviously). Again this morning, the needle shot to H before coming back down around the time the engine finished being warmed up. If the temp light next to the guage lights up at all, it didn't in these circumstances.

So.... are these two problems directly related to the thermostat either being faulty, installed wrong, etc? Or could this be related to another part? This will help me in any sort of warranty I want to have them replace this under (90 day). Same mechanics for 7 years, but still want to be armed with a little more knowledge than what my dad kicks down

Please share with me as much info as you guys can. I would greatly appreciate it!!

-Tim

 

It looks like the thermostat is opening all the way and then closing(repeating). Would explain the heator/temp guage going crazy. It's not uncommon for even new thermostats to be bad. You can take it out and drop it in some hot water, to see when it opens.

 

You might also have air in the system. There is a bleed screw on the top of the intake manifold (by the back - towards firewall, drivers side of car, with a little waring about not removing when the engine is hot). Loosen the screw as the engine is begining to warm up to let the air out.

 

My temp gauge drops way below C and rises up to 1/4 then back down again. the heat isnt very hot when you first start the car either. After a long time, it heats up like normal. Where is the thermostat located? and how hard is it to replace?

 

Thanks a million!

-Tim

 

yup.. I'd put my money on the engine being full of air.. open the valve mentioned earlier to let the air out..

It would be good to pull off the radiator cap (while the engine is cold), and check the fluid level.. if you can pour some in, do so. if it's a small amount, you can probably just fill it with water. if it's really low (which could be possible from what you're describing), use 1/2 water, 1/2 antifreeze.

 

With the DOHC engine the termostate does all the bleeding (its got a little giggle valve on top of it). Its not good to have alot of air in the top of the cooling system, it wont cool the head properly. Does anyone know if the vg thermostate is the same design as the ve. the ve thermo is a thermostatic spring instead of the other kind that uses a pellet which expands.