Club 80-90 Forums

hi guys,after almost 12 months of pretty much trouble free motoring my overheating problems have come back again.....arggghhhhhh!
the weird question is.... with the engine running and dalek cap removed i can see the coolant return to the tank only when i rev the engine at say 3000rpm but its just a pissy little drizzle.is this right? i would have imagined it would have been a pretty strong flow? your thoughts please....cheers ben

thermostat stuck ? maybe pump on the way out

sorry mark i meant to mention that thermostat has been removed,but it was as poor before! pump was from gsf about 13 months ago.i do about 400 miles a week in the van tho so i guess it could be the pump?

belt ok ?

belt is fine mate.i spoke to james earlier but he couldn't remember how the flow was returning to the tank on his,could it be the small bore pipes are blocked?

Liek I said earlier pull pipes off and blow um through check there all clear spoke to a few lads at work and they said the same for the pipes to swell up and bre hard theres either a big amount of air really trapped or a pipe is blocked!

Running without a stat is really asking for trouble.
It's a common mistake to think that no stat = no flow restriction, so no overheating. The pump needs the back pressure to work , otherwise it will just cavitate at higher rpm/impeller speed (that's thrashing around and making bubbles because of no pressure) so you then get localized boiling because the water flow stagnates all over the place.
In racing circles a restrictor disc is used when there's no stat, but the hole size has to be arrived at by experimentation (and using temperature tell-tales).
That's why the flow to the header is a dribble.
Put a new, tested, working stat in and get those pipes checked out, along with your rad before you cook it.

update. i removed most pipes in the engine bay and especially the large clear one that goes all around the bay and i found it was almost completely blocked with a piece of rubber gasket(probably from previous water pump).this along with some "pooh" in another one of the pipes was restricting the flow of coolant around the system!
i cleaned it all out,bled the system and the flow is about 10 times what it was!god knows how i haven't bolloxed the engine altogether but everything seems to be running well at the moment,apart from a small drip coming from the plastic flange pipe that goes to the water pump from the right hand side.hopefully its just the gasket.
cheers guys for the advice