Glosphil Posted April 20, 2008 Share Posted April 20, 2008 Hi Guys I've noticed after a few spirited drives around, that when I turn off the engine, moments later a loud bubbling/gurgling sound appears from the engine bay, on inspection the expansion tank is filling rapidly and bubbling violently. After about 10 mins of bubbling away, it suddenly goes back in the radiators. The level in the tank is also then lower than the max line, but I'd filled it a week ago to the max line. There is evidence that the tank has overflowed. The temperature guage reads normal, the engine bay is hot, but guess thats normal. What is the cause of this? BTW the expansion tank is the one I relcoated with the new one from Greddy when I got my FMIC. Thanks Quote Link to comment Share on other sites More sharing options...
Scooter Posted April 20, 2008 Share Posted April 20, 2008 do you have a relatively new rad cap? Quote Link to comment Share on other sites More sharing options...
Glosphil Posted April 20, 2008 Author Share Posted April 20, 2008 No, its the one it came with? does it make a diff? Quote Link to comment Share on other sites More sharing options...
Scooter Posted April 20, 2008 Share Posted April 20, 2008 No, its the one it came with? does it make a diff? well its my understanding that a weak (ie old) cap can allow more flow into the overflow tank than it should when the engine is up to operating temp....... when its cooled down i'd take the cap off and take a look at the rubber and check the spring, if it looks at all dodgy for the sake of £10-15 i'd get a new one and see if it helps...... Quote Link to comment Share on other sites More sharing options...
absz Posted April 20, 2008 Share Posted April 20, 2008 yep as above its your rad cap Quote Link to comment Share on other sites More sharing options...
Glosphil Posted April 20, 2008 Author Share Posted April 20, 2008 Update on this after reading a bit, I've been out and felt the top of the rad and top rad pipe (got a metal one) both are still hot. top of engine is hot. Bottom rubber rad pipe is cold. If I squeeze it, I hear coolant going through the rad so maybe not blocked? Should the bottom pipe be cold? could the rad cap do this too? Thanks Quote Link to comment Share on other sites More sharing options...
Scooter Posted April 20, 2008 Share Posted April 20, 2008 thermostat is another possibility Quote Link to comment Share on other sites More sharing options...
tooquicktostop Posted April 20, 2008 Share Posted April 20, 2008 Exactly the same as when my thermostat went, very hot top pipe and engine, cold bottom pipe and steam into expansion bottle, I never drove it again until I got it sorted and replaced Quote Link to comment Share on other sites More sharing options...
Glosphil Posted April 20, 2008 Author Share Posted April 20, 2008 ok, further update. took cap off, there is a black washer that fell out as I took it off, put my finger in the hole and removed a smaller black washer and a metal ring. There is no spring? I guess its knackered ! If there is a spring, I guess its in the rad..... what will this do? Quote Link to comment Share on other sites More sharing options...
Glosphil Posted April 20, 2008 Author Share Posted April 20, 2008 Ok after this I've been wondering how it all works, I'm learning a lot changing parts on my supe lol. This interested me, explains how the whole system works. http://auto.howstuffworks.com/cooling-system7.htm Quote Link to comment Share on other sites More sharing options...
Pete Posted April 20, 2008 Share Posted April 20, 2008 Common problem. No pressure in the system, new rad cap required. Happened to me too before CW spotted it. Quote Link to comment Share on other sites More sharing options...
Glosphil Posted April 20, 2008 Author Share Posted April 20, 2008 Yes see that now, but what about the spring? can I just leave it in there? Quote Link to comment Share on other sites More sharing options...
Pete Posted April 21, 2008 Share Posted April 21, 2008 Yes see that now, but what about the spring? can I just leave it in there? If you can't fish it out with a magnet on a stick then it won't do any harm in there. It's too large to get through the thermostat or something I believe? Quote Link to comment Share on other sites More sharing options...
Glosphil Posted April 22, 2008 Author Share Posted April 22, 2008 Ok got a new cap from a local toyota dealer. Is it my imagination or could the car be more responsive now? seems pokier. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted April 22, 2008 Share Posted April 22, 2008 It's your imagination unless it's running a little cooler now. I replace obviously old caps as a service item these days, it's such a common problem. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.