2004 low percolating sound emulating from around engine firewall

[Merlot William]

I am hearing a low percolating sound emulating from around the engine firewall when the engine reaches operating temp and continues after the engine is shut off for 4-6 minutes. Temp gauge never goes beyond normal. Any recommendations where to start diagnosis?

 

[biddle]

Record it, upload the video to YT and post the link here. If not, someone local is going to need to listen.

 

[Pcrpete]

I am hearing a low percolating sound emulating from around the engine firewall when the engine reaches operating temp and continues after the engine is shut off for 4-6 minutes. Temp gauge never goes beyond normal. Any recommendations where to start diagnosis?

I have heard same, and agreed, temp gauge reads normal.
In other news, just drove 600 miles up I-95, plenty of traffic around DC, car ran flawlessly

 

[rjdimonda]

I am hearing a low percolating sound emulating from around the engine firewall when the engine reaches operating temp and continues after the engine is shut off for 4-6 minutes. Temp gauge never goes beyond normal. Any recommendations where to start diagnosis?

A little hard to judge, but it seems like coolant flowing thru the heat exchanger or AC coolant coils under the dash. When you turn on the AC are you getting condensate to run out, i.e., a small puddle under the car. Sometimes the drain on many cars for the condensate is clogged or not draining properly and maybe the residual water stuck around the coolant / heater assembly is making some bubbling noise. Check to see it is draining.

 

[Bobwheeler]

Level normal in the degas bottle? Also, with the engine cold, ck the upper nipple on the degas aka: expansion tank, bottle. Mine broke off when I took it apart. It is a flow through tank, not just in and out. Then follow the vent procedure in the owner's manual (I think that's where it is) if you have to fill or replace the bottle. I have a 2004 with 78K.

 

[Debs tbird]

I have heard similar. I'll have my brother check above steps. I had an 06 Jaguar S type and it did the same noise. Thanks for advice.

 

[Frankie the Fink]

If the temps are normal and the car is not puking or leaking coolant I'd prob just keep an eye on it. You can have the cooling system pressure checked as a precaution and a mechanic's stethoscope can help isolate sounds;

https://www.amazon.com/dp/B07F18V2X8/?tag=thunderbirdforum-20

Some people will use a short length of garden hose to do the same thing.

 

[M. House]

I have heard same, and agreed, temp gauge reads normal.
In other news, just drove 600 miles up I-95, plenty of traffic around DC, car ran flawlessly

Yay for 900! I'm putting my girl back together. The previous weren't kind but we are up to 250.

 

[Merlot William]

Level normal in the degas bottle? Also, with the engine cold, ck the upper nipple on the degas aka: expansion tank, bottle. Mine broke off when I took it apart. It is a flow through tank, not just in and out. Then follow the vent procedure in the owner's manual (I think that's where it is) if you have to fill or replace the bottle. I have a 2004 with 78K.

FYI. I discovered the degas bottle was 28 oz low. filled bottle - drove 10 miles. No more noise - No leaks - anti freeze right at correct mark. have purchased new degas bottle for replacement.

 

[Bobwheeler]

Soundd good. Sorry if I repeat myself. Buy the tank with the hose attached. Trash the old one. Put a little lithium or equal grease on the pipe. Warm the hose with your heat gun and slip it into place using long nedle nose pliers. Put the hose clamp on first aimed up so you can get to it. Use the vent procedure, etc. This is probably old nes but it worked well for me. My normal temp is 220F by OBDII read out. So the sys. is pressurized. I will have to look it up in my CRC Steam Tables. Be sure and do he vnt procdure. Looks like you have a handle on this.

 

[Terry O'Neil]

I had the same problem , It was just that there was some air in the Radiator, all I had to do was flush the air out.

 

[Merlot William]

I had the same problem , It was just that there was some air in the Radiator, all I had to do was flush the air out.

Terry, same thing. after a radiator flush by previous owner air bubble arrived later into the plastic recovery bottle and it was just low on anti freeze. Topped off - everything back to normal. Thanks for your input.