Jump to content
Sign in to follow this  
classic225

foaming coolant

Recommended Posts

Hi Guys,

After a long hard and hot run my 3A always leaks some coolant liquid from the overflow, pretty normal because I keep topping it up. This time I did notice that the coolant was foaming when it overflowed. Checked oil level and that was perfect, drained coolant and did not notice any oil contamination, my first worry was a leak at the liner base. I torqued the head down, but that was OK. so I'm thinking that I'm leaking exhaust gasses in my coolant. Any other theories out there? Could I be able to detect this with a CO gas detector? Or is this no reason for concern as long as oil and coolant stay normal? Just take the head of and have a look?

Thanks,

Yves

Share this post


Link to post
Share on other sites

Hi Yves,

           you should not have your rad filled too high. As long as you can see fluid in the reservoir then that should be fine. 

You can get your local garage to do a gas test in the coolant - Probably get a kit off Ebay.

Don;t take the head off unless you are really sure it is dicky.

 

Roger

Share this post


Link to post
Share on other sites

How old is your water pump?

Perhaps cavitation caused by vanes in inside water pump.

Rod

Share this post


Link to post
Share on other sites

I also have a current problem with coolant on my 3A

Like many, I find the Search Engine a bit tedious, so at the risk of annoying many to have a reply from the few:

My setup is 82° thermostat (no shroud/bellows) Kenlowe pusher fan. 4lb radiator cap.

The coolant temp warms up then suddenly goes up to about 90° And then cools down to 82° Fan cuts in when it should, if it has to. This started a week or so ago Engine running well and ticking over with no lumpiness.

BUT I am losing coolant somewhere. Two observations: the exhaust smoke seems to have more grey vapour than previously and I find there is more back pressure from the oil filler than I would like - fast road engine has about 40 000km since total rebuild some 20 years ago.

I have just changed the thermostat and there is no variation in behaviour. I recently poured in some Bars anti leaks to staunch a very minor leak in the usual place at the top of the rad.

Going to do a compression test when I find a suitable gauge.

Should I suspect a cracked cylinder head?

 

james

Share this post


Link to post
Share on other sites

You may find you get more help if you first try to help yourself James (hint - Google works better than the reg one if you use "TR register" in the search term) and don't you think its a bit off to to hijack someone else's thread, without apology, instead of starting a new one of your own ?

Share this post


Link to post
Share on other sites

Hi Yves,

Warm the car and get it to temperature. drive around for say half an hour.

Park up and remove the rocker cover. check carefully on the side opposite side the carbs and exhaust. There are core plugs which are threaded into the head and then machined flush. I have seen dribbles of water at this point. This seems to be caused by corrosion of dissimilar metals i.e the core plug gets eaten away and eventually becomes holed. 

This may be your issue and could perhaps be cured with something like Barrs leak stop or similar if not then you need to get hold of a plug stick. remove rotten one screw it out with a chisel  and then screw in replacement using Wellseal. Then cut off the excess. if possible it can then be ground flush, factory would machine it off but not absolutely necessary.

They come in a stick of five and are threaded called head core plug

covered extensively on this link

 

Worth a check anyway.

Rod.

Share this post


Link to post
Share on other sites

Thanks for the help and advice.

Yves

Share this post


Link to post
Share on other sites

Head gasket with small leak from cylinder to water jacket. May not show up on compression test till it gets a bit worse.

Share this post


Link to post
Share on other sites

Add a bottle of Steel Seal to your coolant. Relatively cheap (circa £30), it does what it says on the bottle.

Rgds Ian

Share this post


Link to post
Share on other sites
On 7/18/2019 at 11:24 PM, Rodbr said:

Hi Yves,

Warm the car and get it to temperature. drive around for say half an hour.

Park up and remove the rocker cover. check carefully on the side opposite side the carbs and exhaust. There are core plugs which are threaded into the head and then machined flush. I have seen dribbles of water at this point. This seems to be caused by corrosion of dissimilar metals i.e the core plug gets eaten away and eventually becomes holed. 

This may be your issue and could perhaps be cured with something like Barrs leak stop or similar if not then you need to get hold of a plug stick. remove rotten one screw it out with a chisel  and then screw in replacement using Wellseal. Then cut off the excess. if possible it can then be ground flush, factory would machine it off but not absolutely necessary.

They come in a stick of five and are threaded called head core plug

covered extensively on this link

 

Worth a check anyway.

Rod.

My daily driver had a slight weep from the plug. I used J-B Weld over the plug. It is still there 20,000 miles later.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  

×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.