Air pressure in coolant system

[ShadowKnight006]

For some reason my car keeps getting air in the coolant system. I've had it bled by the mechanic 2x and it did it again today. Yesterday there was a leak on the ground under my car and this morning it over heated. I stopped and let it cool and after a while I could hear air escaping (gurgle in the radiator) and coolant had built up in the resevoir and went back down after the sounds. After this it functioned normally. What could be causing this? Radiator or lines? The mechanic said he doubts that it is a leak in the head but could be. Thanks for any help.

--Levi

PS its a 95 240sx

[onosqv]

Simple, air that keeps coming in coolant system = leak somewhere. So just trace the leak! I know, easier said than done.

Here's a possibility, after parking the car, put a large piece of white posterboard/cardboard under the car. That will help you trace leaks. Once you find the source, you can replace the hose/fix whatever.

Have you checked the pressure of your radiator cap? Done an oil change & see if it comes out milky (which indicates coolant -> oil).

[Defiant]

First suspect: cracked overflow tank or its hose.

[180fan]

or the weeper hole at the water pump

[ShadowKnight006]

Thanks for the suggestions, I'm going to try to find it myself because the mechanics around this area don't like taking time to look for stuff.

brokeAs240sx , I did get an oil change done and it was all good. I should get a new radiator cap to be safe, you wouldn't know if the S13 fits would you(I have about 4 of those laying around)?

Defiant, that was one of my first thoughts but thats where the coolant is backing up and it seems to be holding fine.

180fan, I'll check that. Can that be fixed w/o replacing the pump?

There was a puddle under my car but I can't tell where its coming from because the plastic gaurd is still on and redirects everything(I'm going to take it off soon).

Thanks again everyone.

-Levi

[180fan]

yes the s13 rad cap will fit your s14.

coolant out the weeper? replace it.

[rogoman]

For some reason my car keeps getting air in the coolant system. I've had it bled by the mechanic 2x and it did it again today. Yesterday there was a leak on the ground under my car and this morning it over heated. I stopped and let it cool and after a while I could hear air escaping (gurgle in the radiator) and coolant had built up in the resevoir and went back down after the sounds. After this it functioned normally. What could be causing this? Radiator or lines? The mechanic said he doubts that it is a leak in the head but could be. Thanks for any help.

--Levi

PS its a 95 240sx

A strong possibility of a blown head gasket. Perform a compression test on every cylinder.

[Acecool]

put UV dye into the coolant system, directly into the radiator, let it run for a little while and use a uv flashlight to find the leak..

[ShadowKnight006]

I starting to fear it may be the gasket. I was going to put the cap from my s13 on today and noticed that the passenger side of the compartment was covered in coolant, but it was dark so I couldn't really look for where it was coming from(this was at 2am with a flashlight).
Modified by ShadowKnight006 at 5:30 PM 12/4/2006

[Q45tech]

"the mechanics around this area don't like taking time to look for stuff."

A business is a business and expects to get paid their hourly diagnostic rate "to look for stuff" unless you are a good customer already spending a few thousand a year on maintenance and repairs.

[ShadowKnight006]

The fact is I am totally willing to pay for whatever needs done, and my family has been dealing with the same guy, and his dad before him, for 20+ years. Its not a money issue, I just spent $500 there on other repairs while it was supposed to be getting the overheating problem fixed before. So please don't imply that its because I am not willing to pay them to look, I'm sorry if you took offense to that for some reason. The reason we even go to this shop is because he is the best choice in the area but I know he isn't happy about it being a non-domestic.

I'm going there to make another appointment tomorrow, so that maybe I can get it in before x-mas.


Modified by ShadowKnight006 at 5:37 PM 12/4/2006