Vacuum leak and pressurised coolant system

M

mork

Member +
Had an intercooler hose blow off last weekend, had to limp home address is had no tools with me. Put it back together but never drove it until this weekend. Got a whistle at low speed, it's assume there's a vacuum leak somewhere. Seems to boost ok, perhaps not quite as good, so dismantled the pipework from fmic to intake completely and built it back up piece by piece. Still whistling though. All other pipes seem ok, how can I find out where the leak is? I also noticed that the expansion tank is being pressurised. The engine had a rebuild a couple of years ago and is only used occasionally in the summer, has only done a couple thousand miles since then, surely the headgasket hasn't gone already? It's never thrashed, never above 0.8 bar boost. There's no coolant mixing with oil, but it's suddenly started pressuring. Any ideas?
 
R

Rev

Member +
Would locate the whistle exactly if possible. I had small whistle from radiator hose that was not tight enough and this also let some air in the cooling system.
 
M

mork

Member +
If I rev it whilst in neutral it doesn't seem to whistle, only when driving and load is on the engine.
 
B

bongskag

Member +
I had a whistle on my last turbo, it worked good . just sounded like a diesel turbo. that only came on with boost aswell, not revving in neutral.

take your rad cap off and start her from cold. and watch for bubbles maybe ?
 
R

Rev

Member +
If its water the pink toyota fluid leaves a pink powder where the hose has been leaking after it drys out.

bongskag is suggesting you look for bubbles in the radiator water with the cap off and the thermostat ( heated up -open ) because this is a way of checking for head gasket leak
if you are getting unwanted pressure in the radiator it could be combustion gases which you can sometimes see bubble up from below ( not just floating on top ) when you rev the engine slight to moderately.
 
M

mork

Member +
Thanks. I'm thinking the head gasket might be split slighhtly, letting gases through, but I'll run it oer the weekend and see what happens. Back to the boost whistle, what's a good way to check for boost leaks after all joints have been checked and are tight?
 
M

mork

Member +
I'm not sure which ones are vacuum to be honest, but most of the hoses have been replaced with silicon hoses anyway. There are a couple that haven't been done cos I ran out of hose, so I need to get them done.
 
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