Overheating Rover 45

[buzzyb]

I recently had a blown head gasket. The head gasket has been replaced but the overheating problems continue. Even though the head gasket has been replaced the engine still overheats when starting it from cold and travelling at about 55mph or over. If i switch off the engine and wait for the temp guage to come down and then restart the car it is ok. It is also ok when starting from cold if I keep speeds low until the engine has reached normal operating temp and then increase the speed. In all I have had the following items replaced recently:
Cylinder head gasket & bolts, timing belt kit, water pump,thermostat, header tank cap & radiator.
Can anyone tell me why I am still having problems?

Thanks

B

[jomifl]

is the cooling water level staying the same?

[jomifl]

run the car without the thermostat, if it then runs cold you know what the problem is.

[Buenchico]

If car is losing water it might be an imperfect seal after the head gasket repair. (Everything should have been pressure tested upon completion but any decent garage should have also warned you to keep an eye on your coolant level for a week or so after the repair). Take a look at the oil to see whether it looks just like it does when new or if it's acquired 'mayonnaise' on top (which is a sure sign of a recurrence of the head gasket problem).

However, from personal experience, I know of another simple cause of overheating, which is an intermittently working fan. The good news is that replacement fans are cheap (a tenner from a breaker's yard) and easy to fit. So the next time your temperature gauge starts rising beyond normal, open the bonnet and look to see whether the fan is running.

Chris

[buzzyb]

Thanks for the replies.

Coolant levels drop slightly when the car overheats. I can also smell the coolant as the car overheats, but only from the passenger side. The smell only lasts for a few seconds.

The garage put in a new thermostat the other week so I can't imagine there would be a problem with it.

B

[buzzyb]

Thanks Chris, I'm assuming the garage would have carried out the pressure test - well i hope so, the car's been back five times since the gasget was changed. I'll check the oil tomorrow.

Yes, the fan comes on when it overheats so I'm assuming that should be ok.

As I have only basic knowledge of cars I've been dependant on the garage.

B

[Teddio]

You may have an air lock in the cooling system. Drain off all of the coolant into a bucket when the engine is cold.
Add half of the coolant and start the engine.
Slowly add the remainder of the coolant over a period of one minute until it reaches the full level.
This is worth a try and won't cost you anything.

[jake-the-peg]

When the head gasket was replaced was the head skimmed?

The K series engine in the 45 was notorious for head gasket problems - which I'm sure you've been told.

If the engine overheated badly when it went the first time it's possible that the head got slightly warped. If this happened then simply replacing the head gasket without skimming the head to get it back true would cause more head gasket failures.

As Chris says check for water in the oil (Mayonaise) and also smoke (black or white) from the exhaust.

Other overheating problems in older cars can come from dead or dying water pumps or radiators that arent up to the job.

I hate to say this but I have a friend who was recently told that she had a head gasket failure that turned out to be a water pump.

It is possible that you had a failed water pump and someone took one look at the fact that it was a Rover 45 and said it was a head gasket failure, replacing it leaving the original problem unresolved

[buzzyb]

morning all,

many thanks for the advice.

Water pump and radiator have been replaced.

I have checked the oil, that's fine and there's no smoke coming from the exhaust. I guess this means the gasket is ok.

Any other advice?

B

[jake-the-peg]

That just really leaves trivial stuff -

Thermostat obviously I take it that was replaced before shelling out on a new radiator?

Back flush the engine with a hose pipe to make sure that there's no build up of sludge stopping circuation of the coolant.

When filling the system with coolant certain engines have to be bled due to an air pocket forming - usually a bleed screw at the highest point - seen this on citroens for one. Not familliar enough with yours to know if that's the case.

When it overheats do you get hot or cold air out of the heater - if it's cold air you might have trapped air in the system

[AlBags]

You've cracked the head. You didn't have it pressure tested, did you?