200Tdi Head Gasket or Something Else?

[BoyRacerS3]

Hello fellow LR weirdos,

I recently noticed my disco 200tdi engine was seeming to emit steam from under the bonnet in traffic. I put this down to it getting warm having sat for quite a bit stationary, and went on with my day.

It started to get warm again, and I noticed a thin white vapour from under the bonnet, but only in traffic. The temp gauge never went past the middle, even when stopped at red lights etc.

This seemed to get gradually worse, and I checked my radiator this morning and it was probably only a 3rd full.

This engine is in a series 3, but runs disco radiator. The only thing I’m confused about, is there’s no oil in coolant, or vice versa, and there’s no pressure in the cooling system. I am running an overflow bottle and not an expansion tank!

Has anyone got any ideas? I don’t understand why it’s doing this, and I’m nervous to hurt my engine!

Thanks

 

[mikeau]

Any water (steam/vapour) in the exhaust? if not, and there is no oil/water mixing then its less likely (but not impossible) to be head gasket and is probably leaking somewhere!

1/3 full is way too low. You're lucky its not a 300tdi or could have overheated by now (higher pump).

Do you have electric/viscous fan?
If sat stationary for long with no airflow might it be coming out the header tank?
But, when you say no pressure in the cooling system, do you mean even when its hot?

You will need to get it hot again and try to locate where the steam is coming from and trace back from there.

You could try a leak detector kit;

https://amzn.to/3PaUf1X

 

[BoyRacerS3]

Any water (steam/vapour) in the exhaust? if not, and there is no oil/water mixing then its less likely (but not impossible) to be head gasket and is probably leaking somewhere!

1/3 full is way too low. You're lucky its not a 300tdi or could have overheated by now (higher pump).

Do you have electric/viscous fan?
If sat stationary for long with no airflow might it be coming out the header tank?
But, when you say no pressure in the cooling system, do you mean even when its hot?

You will need to get it hot again and try to locate where the steam is coming from and trace back from there.

You could try a leak detector kit;

https://amzn.to/3PaUf1X

I had it hot last night and opened the overflow bottle and radiator cap and no pressure in there, immediately after the weird steam thing.

I didn’t notice any pressure in there, but I guess it would have to be running to really notice this.

Would a proper expansion bottle make this easier to diagnose?

 

[S3Steve]

Hello fellow LR weirdos,

I'd get it full then drive it and check for leaks, ignoring any other thoughts. No point trying to diagnose it on symptoms that present when it was in a bit of a state.

 

[mikeau]

I had it hot last night and opened the overflow bottle and radiator cap and no pressure in there, immediately after the weird steam thing.

I didn’t notice any pressure in there, but I guess it would have to be running to really notice this.

Would a proper expansion bottle make this easier to diagnose?

Dont know which expansion bottle you have. The ones on my Disco1s (200tdi) are the same (black) as I had on the Defender (200tdi) and I swapped them out for the clear type so at least its easier to check if the coolant level drops...

(https://www.island-4x4.co.uk/expans...sr63-pcf101590-clear-fluid-level-p-42721.html)

 

[BoyRacerS3]

I'd get it full then drive it and check for leaks, ignoring any other thoughts. No point trying to diagnose it on symptoms that present when it was in a bit of a state.

Ill take it for a drive, see what comes of it, Ill make sure to fill the whole rad up and see what fluid goes where.

Its got a series 3 expansion bottle on it currently, but the return line is plumbed to nothing, just goes to the ground.

 

[S3Steve]

I've never properly understood how they work, but if you have the Series radiator and cap then I think that should be fine?

 

[mikeau]

If I was running a 200Tdi with the disco rad, I would use the correct expansion tank from the donor vehicle.
Im not saying thats your problem mind...

 

[S3Steve]

This engine is in a series 3, but runs disco radiator.

Ah, I missed that; yeah I'd echo mikeau's advice.

 

[BoyRacerS3]

If I was running a 200Tdi with the disco rad, I would use the correct expansion tank from the donor vehicle.
Im not saying thats your problem mind...

I have a discovery 200tdi expansion tank in the garage, might be worth fitting? I have all the bits, just not got round to it yet. Car has been like it for 18 months with no issues tho…..

 

[mikeau]

Cant do any harm to fit the expansion tank, but keep looking for a leak somewhere...

200Tdi is a cool running engine, thermostats are either 82 or 88 (been checked?)
Do the top/bottom hoses get hot?

This sounds like a simple hose (rad?) leak so far. Head gasket is a leap of thinking from where you are now...

 

[BoyRacerS3]

Cant do any harm to fit the expansion tank, but keep looking for a leak somewhere...

200Tdi is a cool running engine, thermostats are either 82 or 88 (been checked?)
Do the top/bottom hoses get hot?

This sounds like a simple hose (rad?) leak so far. Head gasket is a leap of thinking from where you are now...

I only jumped to the conclusion after the radiator/oil cooler explosion and then being run very low on oil. I kinda feared the worst, but I'll start by assuming its getting hot enough to throw the coolant out of the expansion bottle.

Will report back when Ive taken it for a good run this afternoon/evening.

 

[Kevm]

When it has been running some time and is hot then opening the radiator cap should release serious pressure, dangerous pressure, like squirts hot water in your eyes pressure.
If it doesn't then you have a containment problem.

 

[mikeau]

When it has been running some time and is hot then opening the radiator cap should release serious pressure, dangerous pressure, like squirts hot water in your eyes pressure.
If it doesn't then you have a containment problem.

Ive never found the 200tdi to be very highly pressurised at running temps, which is after all, well below boiling point.
It will release some pressure if you open the cap while its running, I guess the internal temps around the cylinders are high enough, but on the engines Ive had its more of a 'pfffft!'...

I only jumped to the conclusion after the radiator/oil cooler explosion and then being run very low on oil. I kinda feared the worst, but I'll start by assuming its getting hot enough to throw the coolant out of the expansion bottle.

Will report back when Ive taken it for a good run this afternoon/evening.

Hold up!
You never mentioned a ' radiator/oil cooler explosion and then being run very low on oil'...

 

[BoyRacerS3]

Ive never found the 200tdi to be very highly pressurised at running temps, which is after all, well below boiling point.
It will release some pressure if you open the cap while its running, I guess the internal temps around the cylinders are high enough, but on the engines Ive had its more of a 'pfffft!'...


Hold up!
You never mentioned a ' radiator/oil cooler explosion and then being run very low on oil'...

I think I’ve found the source of my problems! The lower thermostat housing has developed a leak, I think.

It’s now chucking coolant out at quite an alarming rate, and leaving a massive puddle on top of the water pump. I guess this means the lower thermostat gasket/housing has gone and needs replacing.

Only issue I can see with this is that the timing cover is in the way?! Is there anything I should be aware of when doing this, and has anyone come across this before? Cheers

PS. Mike, the engine was run low but never out of oil, and compression is still fine. Nothing wrong with it. This was a seperate issue!

 

[Stan the Man]

Ill take it for a drive, see what comes of it, Ill make sure to fill the whole rad up and see what fluid goes where.

Its got a series 3 expansion bottle on it currently, but the return line is plumbed to nothing, just goes to the ground.

That's the overflow bottle .
Just post a photo of what you have got plumbed on at the moment.
It sounds like a right dogs dinner.

 

[mikeau]

Yikes. How bad is it?
Those are like rocking horse poo and expensive on Ebay...
Do you think its the housing itself that has cracked or developed a pinhole?
You may be able to get it welded up if you have anyone capable of doing it, or patch it using JB weld.
Ive heard of top housings corroding, especially around the hose collars, and being repaired but it will obviously depend on how bad it is.

If the timing cover hasnt been off to replace the timing belt or for some other reason then the bolts can be challenging to remove, I would imagine that the bolts holding the housing will be at least as bad. Is it a Disco or Defender engine?
Hope for the best, but be prepared for the worst!

If you are lucky (or did this yourself) then the last person might have put loads of copperslip or anti-seize on the bolts and they will come out easily.
Start getting some releasing fluid on and around any bolts now. Some of those bolts are rather long and the fluid may not penetrate but its worth doing.
You might need some heat so have a decent torch and gas handy (MAP if you have one)
Have a decent drill set and some helicoils on hand.

 

[BoyRacerS3]

Yikes. How bad is it?
Those are like rocking horse poo and expensive on Ebay...
Do you think its the housing itself that has cracked or developed a pinhole?
You may be able to get it welded up if you have anyone capable of doing it, or patch it using JB weld.
Ive heard of top housings corroding, especially around the hose collars, and being repaired but it will obviously depend on how bad it is.

If the timing cover hasnt been off to replace the timing belt or for some other reason then the bolts can be challenging to remove, I would imagine that the bolts holding the housing will be at least as bad. Is it a Disco or Defender engine?
Hope for the best, but be prepared for the worst!

If you are lucky (or did this yourself) then the last person might have put loads of copperslip or anti-seize on the bolts and they will come out easily.
Start getting some releasing fluid on and around any bolts now. Some of those bolts are rather long and the fluid may not penetrate but its worth doing.
You might need some heat so have a decent torch and gas handy (MAP if you have one)
Have a decent drill set and some helicoils on hand.

Ill have to take it to bits to say for sure, but it made a big old puddle on the ground after an hour and a half's driving.

The timing belt cover has already been off recently, about 4 months ago. Will probably just resort to JB weld initially to see if I can sort it that way. Would RadWeld or Steel Seal work in this instance? Bodge fix I know, but I need my car running!

Its a discovery engine, have seen other threads about the bolts being slotted? Does anyone know if they actually are on a standard LR 200 engine or not?

 

[mikeau]

I would avoid radweld or anything you pour into the coolant.
They can work to get you home in an emergency, but Ive read that they can block radiator tubes and build up in the water galleries to cause hotspots etc. If you can identify the crack/pinhole then I would try to do a temporary fix using JB or similar on the outside to plug the leak which would then be ground off when you do the fix.

If you decide to use radweld then plan to do a complete flush afterwards.

I cant recall if the bolts are slotted on the Disco. Its been along time since I last worked on mine.

 

[BoyRacerS3]

I would avoid radweld or anything you pour into the coolant.
They can work to get you home in an emergency, but Ive read that they can block radiator tubes and build up in the water galleries to cause hotspots etc. If you can identify the crack/pinhole then I would try to do a temporary fix using JB or similar on the outside to plug the leak which would then be ground off when you do the fix.

If you decide to use radweld then plan to do a complete flush afterwards.

I cant recall if the bolts are slotted on the Disco. Its been along time since I last worked on mine.

Will do my best to strip it all tonight, identify whats up and get back to you nice people. I'll also test my thermostat, see if that had anything to do with it.