Mopar Muscle Association UK

Getting to the route cause of my overheating problem.

Discovered that it's because the water in the system is being presurised past the radiator cap and out the overflow.

Have changed the cap and it still happens even though the engine is not that warm. Radaitor remains cool but it's still chucking it out of the system.

Could I have a blocked rad?

Can anyone shed some light on this please.....Help gratefully received.

Usually that would be due to a blown head gasket.

I had a similar problem to this. I found that every time I drove my car, the rad would have a . I kept topping up the coolant, but would still do it. Cannonball recommeded that I stopped topping it up, and let the system find it's own level, as indeed it did, and is fine now.

However, my original overheating problem was down to my dissy. I had this re-mapped by Wil (US Imports) to suit my motor - and did the trick

Worked for me - see ifit does for you...?

We had this too, had to recore the rad in the end and it sorted the problem.

[quot
e="Dave"]Usually that would be due to a blown head gasket.[/quote]


sounds like a head gasket , or may be a cracked head or something . might be a silted ( blocked) up rad

My first thought would be head gasket but with no mayo or oily water reckon it can only be blocked.

Think I'll flush the rad and see what comes out.

vipergts wrote:Think I'll flush the rad and see what comes out.

The head gasket can easily blow without any oil getting into the water or water into the oil.

If the rad is that bad it probably will not flush out. Plus the water jacket in the engine may well have two inches of crud trapped in the bottom as well if that is the problem.

Try checking the temp of the radiator core at different points to see how the heat is distributed. Any blocked bits will take longer to heat up.

Radiator is hot at the top middle, cooler down the sides and at the bottom half right accross.

The base of the rad is hot though

I think you need to investigate that a bit more then.

A head gasket would have been a lot cheaper than a re-cored radiator.

Dave wrote:

vipergts wrote:Think I'll flush the rad and see what comes out.

If the rad is that bad it probably will not flush out. Plus the water jacket in the engine may well have two inches of crud trapped in the bottom as well if that is the problem.

We tried flushing and backflushing our system to cure it but it made no difference at all. If the rad core is corroded you're probably going to have to bite the bullet and get it recored' or speak to Wil and get one of his nice ally jobs
If the block is silted up you may have to clear the waterways manually with a wire coat hanger or similar and lots of water.

Yes indeed.....not alot has come out but I'm almost certain it's blocked.......Wil/neil.....I'm gonna be calling you.

If I fit a 26" rad do I need to change the frame it sits in?

Im with Dave, borrow a rad to check it if you think thats what it is, a recore is quite expensive...... to find out its the Head Gasket

The Cuda block had so much silt in it ,it was unbelievable, jet washed that block to hell and back, before the rebuild.

Viper

the size of ally rad depends on rad support opening, if you have a 22" opening there's no point fitting a 26" rad.

You won't have to change the support

If there's any doubt on head gasket do a chemical test, this is 100% and takes 2 minutes, I have the kit which I can post to you if needed.

If the temp of the rad is inconsistant across the surface bearing in mind skin just registers "man that's hot" then the rad is blocked, if you can feel such a big difference certainly side to side then it is blocked.

I have bottles of rad flush and block flush made by Justice Bros in the states, seems to work well and is probably a better first option than taking the motor out.

Lastly once the rad and head gaskets are ruled out 100% it will come down to timing

Wil wrote: If there's any doubt on head gasket do a chemical test, this is 100% and takes 2 minutes

Sounds interesting Neil, how does that work then

Now Gareth that's a good Q

you make sure water is not right up to the neck of the rad, glass chamber over the neck, inside is a liquid that changes colour on exposure to combustion gas, one way suction bulb on the top, air in the top of the rad (not water) is drawn through the liquid if the liquid changes colour from blue to dark green you have a combustion leak into the cooling system.

You can then pull plug leads or slacken off injector pipes on a diesel to determine which cylinders, this bit does take some time as it takes a while for any gas to dissapate so this can upset readings.

It's 100% accurate as long as NO water is drawn up, first bit takes 2 minutes, cylinder ID can take hours