V4 Water leak

[Mikexx]

I thought it was a good idea to add some antifreeze and discovered I had a leak. I initially believed it was in the area of the water-pump but coming from above.

24-11-19 Leak-circled.jpg

Apologies for the camera angle as it may not be obvious of how the photo was taken so this might help.

V4 Engine Arrow.png

A very long while ago I changed the gasket in the inlet manifold and presume that is where the leak is coming from? Is this leak a typical symptom of a manifold failing gasket?

[dumper]

A common problem back in the day was the inlet manifold gasket but from memory it leaked at the rear if you have access to pressure tester try that

[Mikexx]

A common problem back in the day was the inlet manifold gasket but from memory it leaked at the rear if you have access to pressure tester try that

The water level drops and I can collect a load of water from under the engine.

I think this is past pressure testing?

[dumper]

A common problem back in the day was the inlet manifold gasket but from memory it leaked at the rear if you have access to pressure tester try that

The water level drops and I can collect a load of water from under the engine.

I think this is past pressure testing?

Yes but if you can make it come out faster it will be easier to spot if it’s not had antifreeze in it you may have a rotten core plug in the side of the block can’t remember if it has a core plug in the back of the engine inside the bell housing.

[Mikexx]

A common problem back in the day was the inlet manifold gasket but from memory it leaked at the rear if you have access to pressure tester try that

The water level drops and I can collect a load of water from under the engine.

I think this is past pressure testing?

Yes but if you can make it come out faster it will be easier to spot if it’s not had antifreeze in it you may have a rotten core plug in the side of the block can’t remember if it has a core plug in the back of the engine inside the bell housing.

Good call, and I will be able to check without anything rotating trying to remove my fingers. I have a kit somewhere.

No water is coming out of the rear of the engine. It might be an idea to remove the alternator bracket for access.

I'm tempted to tighten the manifold bolts up first, just in case.

[Mikexx]

It's been a while but I thought I would take the manifold off and change the gasket.

All was going well and all done. I emptied the oil as water had entered the bores and some had got into the oil. Bad news.

I had used some silicone sealant and all was water tight.

I waited a day for the oil to arrive and spun on a new filter.

The engine ran fine but when the temperature was raised I began losing water. I had the radiator cap fitter so pressure might have been rising. Some spot again. I was beginning to suspect the head.

I refilled with water and only saw a trickle. Ran the engine and water began to gush out around the front left of the manifold. And I could see a nice pool of water where the distributor sits.

The engine still runs sweetly.

So, next job is to remove the manifold - again. I hate doing things twice.

Is it that difficult to misplace the inlet manifold gasket and cause such a leak?
Can the manifold be cracked?

Any ideas appreciated?

[dumper]

Never used silicone sealer on the gasket always blue hylomar

[Mikexx]

Never used silicone sealer on the gasket always blue hylomar

Thanks, I have used Hylomar in the past too. I now generally use silicone as it sets and stays elastic and non-hardening, where Hylomar can creep (because it doesn't set) and fails.

Most Hylomar gasket sealants such as "Instant Gasket" are claimed to be a RTV silicone sealant.

[Mikexx]

When I removed the inlet manifold for the second time the gasket was well and truly stuck where the gasket material tore leaving gasket material on both the manifold and the heads/block.

I was convinced there was no leak there.

So I fill the system with water with the intention of checking if any water leaked before the water level reached the manifold gasket.

Water started trickling and on removal of the alternator bracket I could see a core-plug had a small hole.

I include a couple of photos. Has anyone managed to change the core-plug without removing the head?

[dumper]

Looking at the photo if there’s enough room to get the old one out and you can drop the new one between plate for the timing gear
and get 1/4 thick steel disc that’s a loose fit in the new core plug so it doesn’t nip when knocking the plug in I would drill a hole in the backing plate big enough to get a punch in the centre of the core plug and try knocking it in square.

Or before you try that maybe you could lever it in square.

If there’s no room for the above maybe dremal the steel plate as close as possible to the timing cover to get enough room to get it in worth a try as it looks like it’s head of timing gear off to fit it
Over the years I’ve used different methods to fit core plugs and damaged them and had to start again with a new plug sometimes you win and sometimes you loose and have to remove more parts of the engine to get the job done.
None of the above may not work but it’s worth a try .

[Mikexx]

Looking at the photo if there’s enough room to get the old one out and you can drop the new one between plate for the timing gear
and get 1/4 thick steel disc that’s a loose fit in the new core plug so it doesn’t nip when knocking the plug in I would drill a hole in the backing plate big enough to get a punch in the centre of the core plug and try knocking it in square.

Or before you try that maybe you could lever it in square.

If there’s no room for the above maybe dremal the steel plate as close as possible to the timing cover to get enough room to get it in worth a try as it looks like it’s head of timing gear off to fit it
Over the years I’ve used different methods to fit core plugs and damaged them and had to start again with a new plug sometimes you win and sometimes you loose and have to remove more parts of the engine to get the job done.
None of the above may not work but it’s worth a try .

I think the photo is a bit deceptive on clearances and tighter than it seems.

I've ordered some core-plugs and will make some decisions on what needs dismantling when the time comes.

If it can't be changed in situ then if needs must I think head off is the easiest way. The timing cover would be a nightmare to remove and it also connects to the sump. My main concern with the head would be the exhaust bolts though perhaps the manifold could be separated from the pipe lower down. We'll see.

[dumper]

Yes head off rather then timing gear which ever way you try to knock in the core plug I made the mistake once of using a too bigger socket and it tightened onto the plug and pulled it back out and damaged it

[Mikexx]

Yes head off rather then timing gear which ever way you try to knock in the core plug I made the mistake once of using a too bigger socket and it tightened onto the plug and pulled it back out and damaged it

Many thanks for the warning.

[Mikexx]

Managed to remove the old and replace without taking the head off.

I had to dismantle the carb to get it to idle! Must remember to use E5 fuel!

[dumper]

Nice one I hope that’s the only one if it’s not had antifreeze in or corrosion inhibitor, if in a hot country it’s possible the rest could be in similar condition.