Heater and coolant problems

[ringo2]

I have encountered a problem with my heater on my 1.8TDDi 75ps 2002 Connect. The heater is fine for a few miles and then blows cold air. However, if I am then at traffic lights or similar and pull away, the heat comes back on for a short time. I also have a loss of coolant - about a mug full every 150 miles. I wonder if they are both related?

[Marty.H]

Get your water system pressure tested to find the leak as a start

[ringo2]

I have just checked over the whole engine for leaks visually, but no evidence at all. A passing local mechanic ('off duty'), tells me that there is a sizeable air lock in the system, as the top hose from the radiator is cool and squishy instead of warm/hot and with water passing through.Also,the small pipe leading back into the expansion tank is pushing bubbly water back in. Should this be just fluid? Any ideas how I can get rid of this air lock please?

[Marty.H]

If it's bubbling in the header could be signs of headgasket failure and would explain why you loosing water get it sniffer tested

[taz666]

the most common cause of coolant loss on a connect is the egr cooler, they leak internally and go straight into the exhaust so you wont find the leak

[ringo2]

Many thanks for the help so far. The head gasket is fine, so egr cooler looks to be the most likely. Is the cooler easy to bypass, and does bypassing cause problems for the egr? Would I need to blank the egr too?

[winterheating]

Make sure you use red antifreeze

[ringo2]

How difficult is it to bypass the cooler? I am pretty confident that I can get hold of the pipe and hose bits. Also, does bypassing the cooler affect the egr? Is it a case of joining up the 2 hoses after disconnecting them from the cooler?

[blue estate]

Yes it's just a case of joining the hoses , why not blank egr

[Turbo Tim]

i had the egr cooler go, smokes like a b*****d, as water is going into the exhaust

[ringo2]

I haven't bypassed my egr cooler yet, but I have replaced my filler cap on the expansion tank. The water level was at max when I left for work(40 miles) and had dropped to min when I got there. I waited a couple of hours and went to see if there was any sign of the level recovering. It hadn't. But, when I removed the new cap to top up for the journey home, there was a gasp of air from the tank,and the level filled up to max again, before my very eyes! What's going on here? I did try to remove a possible air lock the other day by running the engine with no cap on the expansion tank and with heater on hot, but it didn't seem to have any effect.Any one think that the cap may have been the problem?

[winterheating]

That's all completely normal, sounds like you just need a new water pump, if the thermostat is working ok.

Don't put a cheap one on the impellers just disintegrate.