Car overheating!!!

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se4njb7

Fresh Recruit
Right lads, here is the story...

Driving along the road noticed the temp gauge going past half way so stopped and then tried letting the motor cool down.

Got the car back home but had to cruise at 30 and it was still overheating.

Started the car a couple days later to try to figure out what it was. The coolant was bubbling and temp was rising, so cut the engine off.

I tried the engine again but this time I had changed the thermostat, fan switch and also tried the fan directly off the battery to make sure the fan worked. The engine overheated again with coolant boiling, no heat comes out fans in car and idles at 2000rpm... Pretty strange. Also I tried my mates radiator cap and it still does it!!!

So I then changed the head gasket, got a second cylinder head pressure tested, skimmed and valves changed. Got everything back together and still the temp gauge started increasing past half way so had to cut it out just to protect everything. The car still idles at 2000rpm and sometimes jumps up and down between 1500rpm and 2000rpm. There is no heat either out the heater still so I am stumped...

Can anyone give me any ideas??

I think I have noticed the fan doesn't seem to kick in though, I don't know if a relay is goosed but would that cause all the problems?

Cheers!
 
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se4njb7

Fresh Recruit
Cheers lads, will try my other water pump tomorrow as it is pretty much brand new off the other engine. Would it be affecting the fan and idle though? It is one big headache.
 
dac69er

dac69er

Super Moderator
If its overheats in this weather then its likely to be a blockage if the pump is working. Try running without the thermostat fitted. You may have a fan control issue too, but you will want to sort the initial overheating problem first
 
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se4njb7

Fresh Recruit
dac69er said:
If its overheats in this weather then its likely to be a blockage if the pump is working. Try running without the thermostat fitted. You may have a fan control issue too, but you will want to sort the initial overheating problem first
Click to expand...

Tried without thermostat but overheats quicker :S where would a blockage be though? I have checked the pipes from the radiator and water pump. This is doing my head in because I am in desperate need to use the car for work! Which relays are which because I really think one of them has failed or something. Please get back to me with ideas ASAP! Also when the engine is at normal operating temp it still thinks it is cold if it is idling at 2K surely?! Everything was how a normal car would run and idle before this happened.

Cheers guys!
 
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se4njb7

Fresh Recruit
It came has just came to me though. Before all this scenario happened, when I turned the engine off I think it must have been the coolant making a strange kind of glugging noise, any thoughts on that? Blockage somewhere yeh?
 
dac69er

dac69er

Super Moderator
Air lock or blockage, very hard to airlock these engines though! Its not going to be a relay. My fan doesn't even come on in this weather unless i sit in traffic for ages. Flush the rad and flush through the engine block both ways. Try and shift whatever crap may be in the system.
 
R

Rev

Member +
How would you be able to test this?


Flushing can work but some radiator shops would unsolder the radiator end caps and flush the core that way. This way they can then see through the channels if they are blocked or rusted. If ok they would then re solder the end tanks to the core again and pressure test for leaks.
 
dac69er

dac69er

Super Moderator
A new rad can be bought for about £60 so probably as cheap to replace. Try to flush it and you will know if its blocked or not!
 
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se4njb7

Fresh Recruit
Yeh I have flushed rad, seems fine though. However when checking the top rad hose should it not be hard as it pressurizes? Mine does not seem like that and the bottom hose is cold until it gets nearer the thermostat housing, same with all hoses actually except the top one which is hot. I have read up and a coolant temp sensor causes irregular idling and when I disconnect it is still irregular idling, would this be because the coolant isn't circulating properly or is it possibly goosed now?
 
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se4njb7

Fresh Recruit
Totally cleaned out the rad filled back up with antifreeze and still the same. I just can't seem to work out where this blockage is...
 
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Skalabala

Member +
Remove the thermostat and put back the housing.
Then remove top rad hose and use a hose connected to a strong tap and force the water in and use your hand to help the hose seal.
If the water comes out of the rad with great flow then you do not have a blockage in the block or head.
 
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se4njb7

Fresh Recruit
Skalabala said:
Remove the thermostat and put back the housing.
Then remove top rad hose and use a hose connected to a strong tap and force the water in and use your hand to help the hose seal.
If the water comes out of the rad with great flow then you do not have a blockage in the block or head.
Click to expand...

Done that, the water was pouring out so seems good. Changed the ect sensor just incase and now the new one is in it's giving me a diagnostic code of 22 which is a short or open circuit in coolant temp sensor signal which is strange! The old ect sensor however never brung the engine management light on so it's pretty peculiar. Think the car is going to go to a garage tomorrow to see if any mechanics can tell what's going on!
 
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se4njb7

Fresh Recruit
Put the old ect sensor back in to keep the engine management light off. Still overheats and coolant starts to boil, idles at 2K and kind of fuel cuts and revs back to 2K. If I try to hold the revs close to 3K the engine management light comes on and fuel cuts it feels like. I think you'd have to be a NASA engineer to work this shit out to be honest.
 
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