Please Help me and My 318is overheating and very low idle

[Serge88]

I have made too many posts and I apologise from now on I will stick to only this one, firstly I have replaced head gasket, all gaskets, seals, etc.. I put her all back together and I am overheating, I compression tested the engine and she is very healthy sitting at 180psi on all 4 cylinders.

I have tried 2 different thermostats, 2 water pumps, I have bled the system so much that there is barely any coolant left in the system as the water has overcome it. The engine seems to warm up very quickly from cold say approx 4 mins? I have bled the system accordingly including draining rad and block many times

Here is a list of all the items I have replaced

1. All vacuum and rubber fuel hoses
2. All gaskets intake, exhaust, head gasket, timing case profile gasket, valve cover gasket you name it I replaced it.
3. All coolant and radiator hoses
4. Oxygen sensor
5. Throttle Position Sensor
6. Spark plugs
7. Ignition Leads
6. All pulleys
7. All belts
8. Fuel/ Oil/ Air filter
9. Coolant Temperature Sensor (still have issue will get to that)
10. Coolant temperature sending senso (to cluster)
11. Knock sensors x2

The head was machined and pressure tested without any dramas.

Only three concerns are

1. The overheating
2. Very low bumpy idle at approximately 400- 600rpm (nearly stalls
3. Peake Research tool throwing up coolant temp sensor fault

The car is a 1993 318is M42 4Spd Auto.

All the parts are genuine BMW purchased from Pelican parts (cost me an arm and a leg)

There are no other fault codes apart from the coolant temp sensor error, which I figure must be a short or ground within the engine harness, I will get onto that.

What symptoms would arise from coolant temp sensor? bad idle?

She seems to have a slight miss, I will replace the coil pack and new fan clutch and report back...

Any help from anybody would be very highly appreciated as I'm running out of clues, patience and money. Serge

[marti5]

Fan clutch, if when running, get a rolled up news paper and stick it in the fan if the paper stops the fan its the clutch if you get confetti everywhere the clutch is good.

[Serge88]

Thank mate checked the fan clutch and all is well, it seems that my aux fan is not coming on, I have checked all fuses and they seem good, will the aux fan not coming on cause my overheating issue?

[marti5]

Yes the aux fan if not working will cause overheating.It should come one straight away on start up, maybe the motor is shot, see if you can give it a direct feed, then you will know if its gone or not.

[Serge88]

thanks Marti, will get onto it, thanks for your reply, will keep posted.