Overheating but no hot air through blowers

[aidanbree]

I noticed that in traffic on Sunday that my Chim 400 (95) hit the dreaded 100 degrees mark. The traffic started to move at a decent pace and so i decided t move on and let the air hit it. The temperature decreased to around 95ish and I limped it home.

I only got round to checking it out tonight and I noticed that the coolant level wasnt as high as it should be. I put in a good litre in order to bring it around 2inches below the cap. I then took it for a spin and let it sit to ensure everything was OK. The temperature again hit 100 when stationary whilst the fans continue to spin.

2 strange things that I did notice was that the air vents in the car did not heat up and that the usual waft of warm air coming from the bonnet was missing. I suspect therefore I have an issue with the radiator. Can anyone verify this diagnosis from an amateur?

Unfortunately my mechanic borrowed my bible so I am a bit stuck with this. Are there any 'usual' culprits? I cannot see it gushing water....though it has been raining rather a lot recently so it is very difficult to tell!

Cheers

Aidan

[leemarkadams]

One thing it could be is a failed water pump or even a blocked thermostat, as if the water is not being circulated around the cooling system then the hot water will not get to the heater matrix, thus not letting the heater produce any hot air!

I would say that they are worth a try, but then that would not explain the loss of coolant......

Lee

[That Daddy]

leemarkadams said:

One thing it could be is a failed water pump or even a blocked thermostat, as if the water is not being circulated around the cooling system then the hot water will not get to the heater matrix, thus not letting the heater produce any hot air!

I would say that they are worth a try, but then that would not explain the loss of coolant......

Lee

No.but a loss of coolant(or lack of) could explain no heater warmth,when you topped up did you put coolant into the expansion bottle or the swirl pot(one nearest the engine)?

[spend]

Feel the pipes as a quick check if the coolant is flowing. You can with 'knowledge' tell if your rad is cooling by feeling the temp of top & bottom hoses - the difference is quite noticeable (dont burn yourself on the exhaust tho).

Simple things like checking the belt & making sure you dont have a plastic bag blocking the rad... go without saying

Dave

[jsr]

Overheating and no heat through the vents does sound like a lack of coolant. When you topped up the coolant, did you bleed the radiator to remove any trapped air? If not, you may still need to put in a lot more coolant.

[aidanbree]

Thanks for all the suggestions. I will take another look tonight. I didnt bleed the radiator as it appeared not to be dry. I will try that tonight and see what happens.

Cheers

Aidan

[taylormj4]

Hi,
Had this exact problem with mine a few months back.
Serious loss of coolant had occurred. I replaced the coolant using the procedure in SH's book but couldn't find the leak anywhere. Heaters were warm again though.

My garage bloke pressurised the system with a clever gadget that they have and found a leak from the hose that connects to the water pump. The thread on the jubilee clip that secures this pipe had stripped and although it looked fine from the outside and at engine idle, it was letting coolant seep out whilst driving with some pressure in the system.
New jubilee clip and coolant replaced - fine.

Matt

[Chocaholic]

Had a not dissimilar problem a few weeks ago. Temperature gauge hit 100 plus, but no fans came on. Checked the expansion tank, and it was three quarters full. Anyway, got the car trailered in for a pressure check, and it turned out that the radiator had a leak. I assumed it was OK as the expansion tank was full - won't make that mistake again! I also found that the bottom radiator hose had been in contact with the lower pulley Belt and had produced a groove in it that ultimately would have split.

[That Daddy]

Any water level checks should be made at the swirl pot,the other bottle is just an expansion vessel(and no indicator of coolant level in the motor)hot coolant expands and that bottle absorbs the excess until it cools down again.

[aidanbree]

I have just had time to take another look.

I have disconnected the inlet pipe to the radiator. It emptied of water and then I started the car, expecting to see a constant stream of water. I only left the car idling for about a minute or two but there was no more water coming through. I then squeezed the pipe going into the water pump and water came out of the inlet pipe. I think this would indicate that the water pump is not functioning.....is this correct?

I now have my bible back and I have tried to use it to locate the thermostat as another theory might be that it is knackered. I am having difficulty locating it though....Mine is a 400. Can any describe where I should be looking...sorry for the dumb question.

I also removed the oil cap and have found some 'mayo' which I think would indicate that water is getting in. There didnt seem to be much and another post I found seemed to indicate that this may only be condensation related. Hopefully it is.

Thanks again for all the assistance.

Cheers

Aidan

[aidanbree]

On the suggestion of a friend, I decided to reinstate the pipe to the radiator, top up the water and let the car heat up whilst idling. I had some strange results.

When the car hit around 80 degrees, the fans started. I checked the pipes coming in and out of the radiator and both were roasting hot. The radiator also was hot where I am sure that it previously wasnt.

When the car reached 85 degrees, the fans stopped! and quickly the car reached 90 degrees where the fans started again. It stayed at 90 for quite a while and then increased to 95 where it remained.

I left the car for about 20mins maybe more and it stuck at 95 which I think is quite high?

I thought I would take the car for a run and see how it behaved only to find that the clutch refused to work properly. Only getting a little bite at the bottom....think it needs bled...I then realised that I am damned!

Need to get some clutch fluid tomorrow and get it moving!

Could my problem (if it is resolved) have been an airlock?

Cheers

Aidan

[aidanbree]

Aggghh!!!!

Just replaced a bit of clutch fluid and it did the trick. Took the car for a spin and....it started overheating again. I checked the pipe in and out of the radiator and top one was boiling hot whilst the bottom one was freezing cold.

Does this mean that I have an airlock?

[spend]

The thermostat is under the elbow (behind the dizzy) that the hose from your swirl tank connects to. Remove the 2 bolts holding the elbow & the hose to te swirl tank and then the stat pops out. I'd try removing it just to be sure that that is not causing your blockage. When filling up and starting the car you should be able to see water surgeing into the swirl tank.

Take the pipes of the rad and give it a good flushing - it may be blocked (really you need to get the rad out & reverse flush it - but if you disconnect both hoses insitu you can at least check if water is flowing thru the rad)

Dave
PS dont worry about anti-freeze etc, plain water is just fine while you make sure your cooling is working.

[GreenV8S]

If the heater is basically working then hot engine / cold heater is a symptom of a show stopper that can quickly wreck the engine if you keep running it. My advice is stop and make sure you have coolant flow before you do anything else. If you don't have coolant flow (or aren't sure, or don't know how to check) then treat it as a terminal problem and don't let the engine run long enough to get hot until you've fixed it.

Everything you've said so far points to nil coolant flow, there are various possible causes, but until you've fixed the problem you shouldn't run it longer than a couple of minutes and certainly don't drive it. Without coolant flow you can wreck the heads and run up an expensive repair bill very quickly.