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Overheating problems!!..Diesel Hijet 1.2...it's happened so many times now its driven me mad, I can no longer drive the 7 miles into my local town without having to stop at least once to cool down and refill with water. I've tried everything I can think of. I took the thermostat out to see if that was causing the problem, it works fine under the boiling water test but I was surprised when I took it out to find it didn't seem to have a gasket? There was a tiny red rubber ring that fitted in a circular groove in the face of the housing but no normal flat gasket type thingy (is this what it's meant to look like)?
The temperature gauge can swing from hot to cool and back again ridiculously quickly until it decides to carry on to boiling point....again so fast that I barely have time to pull over.
I haven't put the thermostat back in yet but carried on driving it without for a while. I don't bother trying to go anywhere in it anymore.
Obviously I've bled the system many times & followed the procedure detailed in the drivers manual for refilling the cooling system but to no avail,....it still overheats in a very short space of time. I've cleaned up the cap on top of the engine and replaced the rubber washer/seal that had perished somewhat. The last time I took it to the mechanic he diagnosed 'head gasket gone'as there seemed to be a lot of pressure at the radiator when taking the cap off with the water being merely warm-hot. There doesn't appear to be any water in the engine oil at all so I'm not sure if this was said just to get rid of me as he'd been very helpful in letting me use his tools for getting the thermostat out and spent time giving various suggestions without charging me. I'd had to have a new clutch put in at the cost of £250 only weeks before this overheating problem got so persistantly worse, so this was somewhat devastating to hear. I've had my head in the sand for a while over this but am now hoping someone might be able to shed some new light.? I simply cannot afford to get the head gasket done & it not solve the problem.
I'm self-employed & have the catch 22 situation of needing the van for work so have no income without it and have now run out of money to fix or replace it. If anyone has any ideas that haven't already been mentioned in this section I'd love to hear from you.
Hilary 
Errr
One thing you have not mentioned is the water pump, has this been looked at to make sure its actually operating???
Full of ideas but no time to do them!!
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youtube: Redfourtrack
hello there! my parted has a
hello there! my parted has a honda CRX and she had the same problem! everyone thought it was the head gasget! but u can tell if there is water in the oil becasue its milky! and if its in the cylinders because the spark plugs look a funny colour! the next thing i did was a pressure test on the radiator! even tho u could not see any thing or water leaking it was the radiator! its now been replaced and the cooling system has been good as gold since! you could put a bit of rad weld in the system see if that helps! but dont let her over heat to much other wise u will be doing a head gasket!!!
rad?
thanks, the oil is clean, no water hence my query over the diagnosis of a failed head gasket but I haven't checked the spark plugs. When you say a funny colour roughly what colour would that be? Anything other than black or grey I'd guess? I did put some rad weld in it before taking out the thermostat some weeks ago but I think that marked the time it started getting particularly worse, so I don't know if it created an additional problem or simply made the existing cause worse. How did you do a pressure test on the radiator? Apparently there is a lot of pressure on mine when removing the cap when warm and that's what made the mechanic think it was the head gasket? was your pressure high or low?
cheers
Hilary
yes water pump! try that!
yes water pump! try that! dont know if there belt driven but check the belt and make sure its tight if it has not snapped! if the belts are still there take it appart and check! the fins there metal and dont normaly break! but when u put the pump back on u can get locktight water pump sealent from ya local halfords rather than getting a new gasket ordered
Check.
You say the thermostat is removed. So no need to try this at normal temp, it should show at cold:-
Remove the radiator cap. Run the engine at idle.Look down into the radiator filler whilst the rad cap is removed. Rev the engine fairly high. Note if the coolant level rises or lifts up the radiator filler hole. The level should noticable rise.
If there is no 'lift' of the coolant level then its a sign that the water pump is not working and coolant is not circulating.Remove/replace the water pump.
No 'rise' could also be due to a blocked radiator. When the coolant is boiling, feel if the rad is hot at the bottom but cold at the top. If the temp range is very noticable the problem could be a blocked radiator. If the car is 10years old then thoroughly flush the radiator or use a radiator-flush then hosepipe. However the hot/cold rad is also symptomatic of a failed water pump.
If coolant 'rises' in the rad filler hole, then assume the water pump is circulating coolant. The belt could be spinning the visible pulley but the internal shaft of the pump could be snapped or its bearing so badly corroded that its efficiency is useless.
However if air bubbles escape from the filler hole then assume an air leak from either a hose or more likely from a failed heat gasket. If head gasket has failed the bubbles will be more noticable when the coolant is hot.
If the coolant reqularily needs topping and no visible hose leaks noticable, then I would assume the head gasket is the problem. Coolant is being sucked into the cylinders and escapes with the exhaust. Is the hot exhaust noticably wet? Hold a clean dry cloth over the exhaust ... lots of water?
However ....... is the carpet wet down the side of the footwell adjacent the heater box? If it is wet the the heater matrix is leaking. Air gets drawn into the system to replace the lost water and an air lock can give the over heating condition. Check the carpet for damp .... not the floor but down the sides of the foot well.
Hi-Jet problems
Hi.
You may have looked at these posts, but I have noticed a lot of posts by a member 'harvey'. He has made lots of posts re Hi-Jets overheating. Do a search for his posts, or contact him by PM (CLICK ON HIS NAME). He seems to be the guy to contact Re Hi-Jet problems.( seems to be a helpful guy)
Edward (ews) '92 Fourtrak 2.8 TDX
hot hijet
Check the seal on both RAD caps and spray/clean the terminals on the fan thermostat switch. If when warm the hoses are soft then the system isn't pressurising and the water will then boil. It is common on the Hijets and I had the same and both the above have kept it cool. If it gets a bit hot then I used to turn the heater on and blower which increased circulation and cooling. Noe the new owner still has no further problems as I work with him.
GOOD LUCK
OLDMINIMAN
M J Young
head gasket
Mate, it sounds like the head gasket... these are NOT as bad as it sound..... just bacause there is no water in oil does not mean the gasket has not gone..... do not forget there is also the exhaust ports to think about. however, if the gasket does pop between the water and exhaust you usally get to see nice white smoke (which is actually steam) coming out of the exhaust, and they tend to run like a bag of nails.. but if the exhaust is pressuring the coolant system then you water will piss out the burp bottle or similar.
Cheers
H
Cheers
H