Loud noise from the Thermostat houseing??

[Shandon]

I replaced my thermosat some time ago with a 170 from Roe. When the car would get over 200 degrees I could hear a somewhat loud buzzing noise and it comes directly from where the thermostat is housed. I just recently had DCPerfomace flash my PCM and one of the things they did was make fan/temp changes. My question is this...Is it normal to hear a pretty loud sound coming from that area when the car reaches the temperature that is designed to turn the fan on high. It goes completely away when the temperature goes down??? Maybe I need a new thermostat? Or this is normal. NOTE: It is loud enough to hear over the engine when you rev it...

Any help or thoughts would be great.

 

[adamlotus]

onmy 08 when temperatue outside is hot and engine is warm and if i go over 5000 rpms i hear a whinning noise from the fan area.

 

[dave6666]

I've heard of fan issues on the Gen 3's, but there have also been some threads recently on bad t-stats in some Gen 2's. Are you convinced it's from the t-stat area and not the fan area?

Also, try a automotive stethoscope and see if that can help pin it down.

 

[mjorgensen Woodhouse]

I would be suspect of the stat also and would call DCP and have it switched out. It could be stuck or the "spring" could be broken.

 

[Shandon]

Well i changed out the thermostat again today and replaced it with a new one from Parts Rack. Waaa Laa Fixed!!! No more noise at any water temp level. Maybe someone could chim in on what I found though?

The thermostat I got from Roe Racing a long time ago was a 170 or something like that and the one I got from John B is also a 170. I compared the two before installation and found the one from roe (causing the noise)was about 1/4" longer and I think what was happening is that the brass looking top of the thermostat was coming into contact with the back of the housing when the temp would increase. I am wondering if they sent me the wrong thermostat? Is there a difference in Gen 3 and Gen 1,2 thermostats? Just curious? Not going to try ang get money back if there is. Didn't cause any issues other than some extra grease under the nails. NOTE: (The only differences between the thermostats was the brass top in the roe racing one being longer. The rest looked identical)

Thanks again to those who chimed in on this!! It helped!

 

[MikeR]

I may have to try this also. I have been battling this similar noise. I replaced my P/S pump, it was getting real noisy. But I still have a simialr noise to when pump was acting up. Its a loud whine after car gets over 180 degrees. As car cools a bit noise comes and goes. I can hear it over engine. Its from engine area, but I hear through vents/dash while driving.
If its not the TSTAT like you, then it could be the fan. Ive only had this problem as of this year, after installing 170 stat and turning on fans earlier. Hmmm, what to do....

 

[Viper X]

I've had a few issues with T-stats in my 04 SRT-10, but no noise that I could tell (engine is pretty loud). I replaced the OE T-stat with a 180F aftermarket unit and found it too did not fit very well. It also made my engine run a bit warmer than it should.

I then replaced the 180F with another aftermarket 170F T-stat and when I compared the two out of the car, they were slightly different lenghts, with the longer one (180F) causing the engine to run 15 to 20 degrees warmer during the summer at cruise and quite a bit warmer under load.

I bought another 170F T-stat and put both it and the 180F into a pan of boiling water. The 170 F T-stat opened sooner (which you would expect), but it also opened much more widely, allowing much better coolant flow than the 180 F T-stat.

All T-stats are not created equal.

All is now good, car runs cool.

Dan

 

[Nader]

This might sound like a silly question but are you sure you are not hearing the hydraulic fan?

 

[Shandon]

This might sound like a silly question but are you sure you are not hearing the hydraulic fan?

The noise I had was a direct result of the thermostat (at least that fixed it anyway). Not only was it loud enough to be heard over the engine (all the way up to 5K when reving) there was a fast vibration that I could feel on the outside of the thermostat housing. Im not sure what the thermostat presses against when it expands but whatever the case the new shorter 170' one solved everything. The car runs the same but when the temp gets up and the fan comes on high there is no noise and I can rev the engine while under the hood and again no loud sound.

 

[Shandon]

I may have to try this also. I have been battling this similar noise. I replaced my P/S pump, it was getting real noisy. But I still have a simialr noise to when pump was acting up. Its a loud whine after car gets over 180 degrees. As car cools a bit noise comes and goes. I can hear it over engine. Its from engine area, but I hear through vents/dash while driving.
If its not the TSTAT like you, then it could be the fan. Ive only had this problem as of this year, after installing 170 stat and turning on fans earlier. Hmmm, what to do....

I use to only notice the sound when the temp would get up to 210 but then the fan would come on high and the temps fall and thus the noise goes away. Then I had DC flash the PCM and make the fan come on earlier and then I started realy hearing it at a much lower temp like 190 or so. Yes you can hear it over the engine through the whole rpm range. I would suspect you have the same issue. I know that the fan is hydraulic and come on by something that the thermostat does when expanding. Anyway whatever the case this seemed to fix it for me.

 

[Nader]

Well I am glad it is fixed.