HELP: Overheating
HELP: Overheating
My FB wont stop overheating. It keeps going and going, but the little red temp light doesn't like to turn off. In the past I have tried radiator flush powder, new coolant etc, and more recently I installed another radiator with if anything worse overheating. Just now it split the bottom radiator hose. Could my head have blockages in it? I am not so keen to spend big on a radiator as I will soon be installing an rb30et into the fb, so the inlet and outlet positions will be different, and I would like to buy a new radiator to suit the new engine, not the old red.
Any help would be great.
Andrew
Any help would be great.
Andrew
Craig wrote: Andrew you have a red so I wouldn't race it![]()

Hi Andrew,
something doesn't sound right here - I wonder if there's something in the lower hose...?
Yes, you seem to be stuck between a rock and a hard place - with that intended implant - I have an absolute stock standard HK/T/G six radiator in mine - but of course the sides of the baffle had to be cut away to fit it.....
Again, you probably don't want to hear all this as you will need something bigger with the rb30..
There is always a risk when you run a cleaner through a cooling system - the fine crap blocks the thin tubes - usually in the top tank of the radiator - that's the place where the narrowest passages are - my only suggestion is to pop the radiator out - turn it upside down and run a hose through it - a couple of times through the (actual) lower hose fitting then invert it and flush anything from the lower tank out - you can do this a number of times - if you do see rusted crap, silicone sealant breakages or anything other than water - you need to keep going....
Careful when doing this with a hose - do not be tempted to put full pressure into it, Andrew - they are designed for around 13 lbs max - and that is not hydro-static as water will be supplied from a hose - make sure you leave the top of the radiator open - both the cap and top hose connections free to allow any crud out.....
Some people use water and compressed air - a gently flush with both at the same time often brings results - but GENTLE
You will most likely find that the block and head have much of this stuff laying around as residue - and it settles in parts which are not in the direct flow of coolant - the block is a particularly bad design for this - there seems to be a "sump" where this stuff takes up residence - if you have used a cleaner - it may have been disturbed and gone into solution - eventually finding its way to the tube openings at the top of your radialtor......
but.... the split bottom hose....hmmmm
Does your radiator cap fit properly and does it release pressure over it's rating.... for the life of me at present I cannot understand why the problem would split the hose - I could understand the top hose - but the lower one is under "suction" from the water pump - if you like......
the lower hose has a spring in it to prevent it squashing (collapsing) under the draw of the water pump...... but to have it split.... I'm intrigued.... -
when you say you can't get it back on - I don't suppose for some reason there is a bend in it which is restricting the passage of coolant.
If there has been one fitted which is too long - it may very well be doubled back on itself slightly and this may be restricting the flow..... that would explain over-heating......
And - temp lights..... usually come on just as damage is happening - please do not run with this light on - pull over, stop the engine and let it cool out a bit before looking for the cause - I am probably professing to what you already know - Andrew - but others read our posts and these extra lines may prevent them destroying their engine or burning themselves...... please tolerate my expansion.....
The temp light is the only one which doesn't "self test" when you first turn the key on - in other words - it doesn't "rest" in the "warn" position.....
If at any time this light comes on - it is screaming at you to take immediate action.....
and - there is always the possibility that the temperature sending unit is shorted - or wiring ..... but this I feel is not your problem.....
If the light is on, STOP the engine and very carefully feel the lower hose -and bottom of the radiator - if they are cool and you know the thermostat to be opening, there is a strong indication that your sender unit is shot..... if either or both are boiling hot - then you have problems.....I would then go back to the radiator cap and top hose...... try to find a largish rag and get it really sopping wet.....
The radiator cap has a primary release position - with this wet rag over the cap - turn it to this first position - this should permit the pressure to escape through the over-flow hose - you must remember that the boiling point of water/coolant is increased under pressure - what you are going to do is relieve that pressure - if it wasn't boiling, it most likely will when you move the cap to the first stop - be warned - it will burst out from the over-flow hose and an unwary leg is not going to offer any resistance.........
only after doing this can you open the cap fully and very carefully remove it - still with the wet rag over the area....
If your coolant is not showing - never, never never fill it with the engine hot - you may crack any part of the engine's cooling jackets or even the head......
If you MUST add coolant (and there is some still in there) - you may do this after a reasonable cool off and with the engine just idling - SLOWLY add coolant/water until it is within the normal range or level......
I have been thinking on a split hose whilst typing this out, Andrew and still cannot fathom why...... I am very much intrigued.....
guess I'll have to leave this one to someone who has had the problem - but I want to know......
frats,
Rosco
something doesn't sound right here - I wonder if there's something in the lower hose...?
Yes, you seem to be stuck between a rock and a hard place - with that intended implant - I have an absolute stock standard HK/T/G six radiator in mine - but of course the sides of the baffle had to be cut away to fit it.....
Again, you probably don't want to hear all this as you will need something bigger with the rb30..
There is always a risk when you run a cleaner through a cooling system - the fine crap blocks the thin tubes - usually in the top tank of the radiator - that's the place where the narrowest passages are - my only suggestion is to pop the radiator out - turn it upside down and run a hose through it - a couple of times through the (actual) lower hose fitting then invert it and flush anything from the lower tank out - you can do this a number of times - if you do see rusted crap, silicone sealant breakages or anything other than water - you need to keep going....
Careful when doing this with a hose - do not be tempted to put full pressure into it, Andrew - they are designed for around 13 lbs max - and that is not hydro-static as water will be supplied from a hose - make sure you leave the top of the radiator open - both the cap and top hose connections free to allow any crud out.....
Some people use water and compressed air - a gently flush with both at the same time often brings results - but GENTLE
You will most likely find that the block and head have much of this stuff laying around as residue - and it settles in parts which are not in the direct flow of coolant - the block is a particularly bad design for this - there seems to be a "sump" where this stuff takes up residence - if you have used a cleaner - it may have been disturbed and gone into solution - eventually finding its way to the tube openings at the top of your radialtor......
but.... the split bottom hose....hmmmm
Does your radiator cap fit properly and does it release pressure over it's rating.... for the life of me at present I cannot understand why the problem would split the hose - I could understand the top hose - but the lower one is under "suction" from the water pump - if you like......
the lower hose has a spring in it to prevent it squashing (collapsing) under the draw of the water pump...... but to have it split.... I'm intrigued.... -
when you say you can't get it back on - I don't suppose for some reason there is a bend in it which is restricting the passage of coolant.
If there has been one fitted which is too long - it may very well be doubled back on itself slightly and this may be restricting the flow..... that would explain over-heating......
And - temp lights..... usually come on just as damage is happening - please do not run with this light on - pull over, stop the engine and let it cool out a bit before looking for the cause - I am probably professing to what you already know - Andrew - but others read our posts and these extra lines may prevent them destroying their engine or burning themselves...... please tolerate my expansion.....
The temp light is the only one which doesn't "self test" when you first turn the key on - in other words - it doesn't "rest" in the "warn" position.....
If at any time this light comes on - it is screaming at you to take immediate action.....
and - there is always the possibility that the temperature sending unit is shorted - or wiring ..... but this I feel is not your problem.....
If the light is on, STOP the engine and very carefully feel the lower hose -and bottom of the radiator - if they are cool and you know the thermostat to be opening, there is a strong indication that your sender unit is shot..... if either or both are boiling hot - then you have problems.....I would then go back to the radiator cap and top hose...... try to find a largish rag and get it really sopping wet.....
The radiator cap has a primary release position - with this wet rag over the cap - turn it to this first position - this should permit the pressure to escape through the over-flow hose - you must remember that the boiling point of water/coolant is increased under pressure - what you are going to do is relieve that pressure - if it wasn't boiling, it most likely will when you move the cap to the first stop - be warned - it will burst out from the over-flow hose and an unwary leg is not going to offer any resistance.........
only after doing this can you open the cap fully and very carefully remove it - still with the wet rag over the area....
If your coolant is not showing - never, never never fill it with the engine hot - you may crack any part of the engine's cooling jackets or even the head......
If you MUST add coolant (and there is some still in there) - you may do this after a reasonable cool off and with the engine just idling - SLOWLY add coolant/water until it is within the normal range or level......
I have been thinking on a split hose whilst typing this out, Andrew and still cannot fathom why...... I am very much intrigued.....
guess I'll have to leave this one to someone who has had the problem - but I want to know......
frats,
Rosco
Last edited by rosco on Fri Dec 26, 2008 7:59 am, edited 2 times in total.
-
artyfartymarty
- Posts: 319
- Joined: Fri Sep 05, 2008 6:39 pm
- State: WA
- Location: Doubleview Perth WA
if you suspect the thermostat, run the car without it for a while to see if it makes any difference, it won't hurt it as long as you don't tramp the loud pedal within the first 5 minutes of a cold start. then check the water pump for flow, blah, blah blah...save yourself time, pain, headaches and take it to someone who has knowlege, experience and the right tools for the job, get them to look over it and ask for an itemised quote, compare that with others for peace of mind to comfort yourself your not being robbed.
now, can you do the work yourself? if so work out how long it would take you to do what is required and ask if yourself if you are better off to do it yourself or pay the man the money he has earned for the work you had asked to be done and get on with doing what you do best, c's you may end up spending a lot of money replacing everything associated with cooling and a week of your time dicking around and end up with a half arsed job that you wouldn't accept if someone else had done it for you c's it still gets hot.
It may be as simple as a high pressure reverse engine flush to remove all the crud from the motor. Can you do that at home with the garden hose?
now, can you do the work yourself? if so work out how long it would take you to do what is required and ask if yourself if you are better off to do it yourself or pay the man the money he has earned for the work you had asked to be done and get on with doing what you do best, c's you may end up spending a lot of money replacing everything associated with cooling and a week of your time dicking around and end up with a half arsed job that you wouldn't accept if someone else had done it for you c's it still gets hot.
It may be as simple as a high pressure reverse engine flush to remove all the crud from the motor. Can you do that at home with the garden hose?
Last edited by artyfartymarty on Fri Dec 26, 2008 1:05 am, edited 1 time in total.
FB EK Club WA
Don't follow me, I'm lost too
Don't follow me, I'm lost too
-
artyfartymarty
- Posts: 319
- Joined: Fri Sep 05, 2008 6:39 pm
- State: WA
- Location: Doubleview Perth WA
youre just guessing...
get someone who looks at radiators every day of the week to give you an opinion. it really may be as simple as decent flush. it may be that both radiators are cactus. i was driving around a few years ago in an old subaru that used to get hot in the sand only. had the cores cleaned out. it turned out 70% of the cores were blocked solid. it just needed the cores of the radiator cleaned out. I had spent a small fortune in flushing products before i gave up and took it in to someone...
don't copy my experience, benefit from my mistake.
get someone who looks at radiators every day of the week to give you an opinion. it really may be as simple as decent flush. it may be that both radiators are cactus. i was driving around a few years ago in an old subaru that used to get hot in the sand only. had the cores cleaned out. it turned out 70% of the cores were blocked solid. it just needed the cores of the radiator cleaned out. I had spent a small fortune in flushing products before i gave up and took it in to someone...
don't copy my experience, benefit from my mistake.
FB EK Club WA
Don't follow me, I'm lost too
Don't follow me, I'm lost too
artyfartymarty wrote:youre just guessing...
get someone who looks at radiators every day of the week to give you an opinion. it really may be as simple as decent flush. it may be that both radiators are cactus. i was driving around a few years ago in an old subaru that used to get hot in the sand only. had the cores cleaned out. it turned out 70% of the cores were blocked solid. it just needed the cores of the radiator cleaned out. I had spent a small fortune in flushing products before i gave up and took it in to someone...
don't copy my experience, benefit from my mistake.
Good point. I had a 351 V8 that was having savage overheating problems. I spent a fortune trying to fix other problems which I thought were causing it.
it was a simple case of having the radiator professionally flushed/cleaned.
-
mrs ratbox
good tip to give you an idea of if the radiator is blocked
remove bottom radiator hose off the radiator
cover outlet with yor hand
fill radiator
when full remove hand
radiator should empty very fast if you get the water emptying slowly it's usually a sign it's blocked
also radiator by itself should hold a few litres of water
also the other radiator hose you fitted was it new? there should be a spring inside it to stop the hose collapsing
remove bottom radiator hose off the radiator
cover outlet with yor hand
fill radiator
when full remove hand
radiator should empty very fast if you get the water emptying slowly it's usually a sign it's blocked
also radiator by itself should hold a few litres of water
also the other radiator hose you fitted was it new? there should be a spring inside it to stop the hose collapsing
RB - I did something similar to what you suggested when the radiator was first purchased and I thought it was flowing well. I am too pissed off to try anything else now. As for the hose - it doesn't have a spring in it. It is hard to put on because of where the engine is positioned - it further forward than out ek. The split occured inline with where the hose meets the radiator barb making me think that it was under undue stress causing it to break. I have reused the hose for the time being by cutting it slightly shorter, which has made it fit better.
This one has me and my Dad baffled - it is now a problem for the professionals.
This one has me and my Dad baffled - it is now a problem for the professionals.
Craig wrote: Andrew you have a red so I wouldn't race it![]()
