gurggling sound from radiator coolant overflow tank normal??

surferboy · Post by **surferboy** » Mon Jul 06, 2015 1:22 pm

Hello all, last year I had the discontentment of finding out that I had a cracked engine head in my '93 L300.
What prompted me to investigate the problem was that I was hearing a gurggling noise from what seem to come from under the passenger seat after turning the van off. I had never noticed this before so I looked at engine compartment and after some further investigation, I realized that my coolant levels in radiator was very low and that the gurgling noise was probably due to back pressure... Took the van to CC Auto in Coombs where they confirmed the problem and proceeded to replace the head.
Shortly after head replacement plus a bunch more work done while at it, I still could hear the gurgling sound from the coolant over flow tank.
I called back CC Auto which confirmed that unless the van was overheating and was low on coolant, that this was likely caused from excess coolant returning from radiator into overflow tank and to not worry about it.

Has anyone noticed this noise on their vehicles? I am somewhat not convinced that this is normal, I'm thinking back pressure which I was told isn't good.
The van is not overheating and has coolant in rad, The head was replaced last September (2014).

Any words of wisdom welcome!
Cheers!

Tojo · Post by **Tojo** » Mon Jul 06, 2015 2:52 pm

Did they replace the radiator cap?

surferboy · Post by **surferboy** » Mon Jul 06, 2015 2:57 pm

Hi Tojo, I believe that they would have pressure-checked it. This was done by CC Autos, they know what they are doing..

Tojo · Post by **Tojo** » Mon Jul 06, 2015 3:02 pm

Yes, I've bought parts from Graham, and visited their shop. Very knowledgeable.

Check your invoice though, and see if they replaced the cap. Also see if they replaced the thermostat. Pressure testing the rad will tell you if there are leaks in the system, but an older radiator cap will have a weak spring and seal and tends to release coolant at a lower pressure, especially with this heat wave we're having.

surferboy · Post by **surferboy** » Mon Jul 06, 2015 3:12 pm

Ok Thanks, i will double check the invoice, do you think that the gurgling noise is abnormal then?

surferboy · Post by **surferboy** » Mon Jul 06, 2015 3:15 pm

Oh, and I know that the Thermostat was changed...

Tojo · Post by **Tojo** » Mon Jul 06, 2015 3:33 pm

Coolant should be able to flow freely from the radiator to the overflow when the motor is hot, then get sucked back into the radiator as the pressure drops. But mine has never made a gurgling sound.

What I like to do is take a sharpee pen and draw a line on the side of the overflow tank to mark the coolant level when the engine is cold. Then after a long weekend of logging roads and hauling heavy loads, check and see if the coolant is at the same mark.

surferboy · Post by **surferboy** » Mon Jul 06, 2015 4:00 pm

Ok will try that, check if rad cap has been replaced and maybe get a pressure test done at a shop to make sure all s OK?

Tojo · Post by **Tojo** » Mon Jul 06, 2015 4:14 pm

Radiator cap is cheap. If it looks old, then replace it. Pressure test won't diagnose a failed cap as the test requires the removal of the cap itself. Here is how it's done: https://www.youtube.com/watch?v=K5p-G3UDi-A
Eric the Car Guy is also a great teacher in other areas of auto repair. Can you take it back to CC Autos?

surferboy · Post by **surferboy** » Mon Jul 06, 2015 4:19 pm

Trying to avoid another trip up island from Sooke where I live, I called them about this a month ago or so and Graham said that if van doesn't overheat and that rad fluid levels stay the same, then to not worry about anything...where do I get a new rad cap for those vans down in Vic area?

Tojo · Post by **Tojo** » Mon Jul 06, 2015 4:22 pm

Rocky Mountain Imports is near you: http://www.rockymountainimports.net/index.php

DexterH · Post by **DexterH** » Wed Jul 08, 2015 11:41 am

Hi there. I live in the Caribbean and its tropical weather here and contributes to excessive heat on our engines. I rebuilt my 4d56 October last year and Ive had that same gurggling sound. I couldnt recall the engine doing that before rebuild but in the 9 months since then, I always hear it, especially on very hot days and moreso when I'm using the a/c.
All I can theorise is that after a certain pressure is reached in the radiator and 'x' amount of coolant is dumped into the overflow, there is possibly air buildup on the top of the radiator. The coolant level is at a level thats too low to reach and exit the radiator to the overrlow and instead its the air pressure buildup that exits instead. Hence the gurggling (air bubbles).

Im not sure whats causing the air pressure buildup though but my engine worked fine.
However! Two days ago my timing belt snapped thats what brought me here. I highly doubt that gurggling had anything to do with the belt snapping and the engine was perfectly timed.

Hope you get that gurggling sorted. I didnt try replacing the cap, but I'll give it a try after the repairs are done.

Thanks guys.

Delica Canada | Mitsubishi Van Club

gurggling sound from radiator coolant overflow tank normal??

gurggling sound from radiator coolant overflow tank normal??

Re: gurggling sound from radiator coolant overflow tank normal??

Re: gurggling sound from radiator coolant overflow tank normal??

Re: gurggling sound from radiator coolant overflow tank normal??

Re: gurggling sound from radiator coolant overflow tank normal??

Re: gurggling sound from radiator coolant overflow tank normal??

Re: gurggling sound from radiator coolant overflow tank normal??

Re: gurggling sound from radiator coolant overflow tank normal??

Re: gurggling sound from radiator coolant overflow tank normal??

Re: gurggling sound from radiator coolant overflow tank normal??

Re: gurggling sound from radiator coolant overflow tank normal??

Re: gurggling sound from radiator coolant overflow tank normal??