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GTRekky

Member
Hey forum,

I've got a TD5 and the coolant level indicator light came on at the weekend. I topped it up with around 1.5 litres of water and after a 30 odd mile trip, it had emptied the expansion tank again.

After starting it the following morning, I noticed a considerable amount of white smoke from the exhaust, however this only lasted for a couple of minutes whilst the engine was cold.

I used an RELD block test head gasket tester to see if my suspicions of a blown head gasket were correct, but the liquid remained blue and passed the test with flying colours.

I'm assuming the coolant is entering the combustion chamber which is why there is white smoke (steam?) on start-up, but why would it then pass a head gasket block test?

Could it be cracked head? Fuel cooler?...

Any advice is greatly appreciated.

Thanks,
GTR.
 
I expect because no burnt fuel is entering the coolant.
It depends on where the crack/break is in the head gasket. For the stuff to change colour the crack has to be between the cylinder part of the gasket and the coolant which is still circulating around. If it sucks coolant in then just blows it out via the exhaust.....
 
GTRekky said:
Hey forum,

I've got a TD5 and the coolant level indicator light came on at the weekend. I topped it up with around 1.5 litres of water and after a 30 odd mile trip, it had emptied the expansion tank again.

After starting it the following morning, I noticed a considerable amount of white smoke from the exhaust, however this only lasted for a couple of minutes whilst the engine was cold.

I used an RELD block test head gasket tester to see if my suspicions of a blown head gasket were correct, but the liquid remained blue and passed the test with flying colours.

I'm assuming the coolant is entering the combustion chamber which is why there is white smoke (steam?) on start-up, but why would it then pass a head gasket block test?

Could it be cracked head? Fuel cooler?...

Any advice is greatly appreciated.

Thanks,
GTR.
Click to expand...
Those chemical testers rarely work on Td5's. Presumably you have an aftermarket coolant level sensor installed ?
 
tom1979 said:
Those chemical testers rarely work on Td5's. Presumably you have an aftermarket coolant level sensor installed ?
Click to expand...
Thanks for the reply Tom,

I don't have an aftermarket coolant level sensor installed atm.

I assumed this light meant low coolant but will happily be corrected :)
 
GTRekky said:
Thanks for the reply Tom,

I don't have an aftermarket coolant level sensor installed atm.

I assumed this light meant low coolant but will happily be corrected :)
Click to expand...

The light in that photo is the automatic gearbox temperature

The coolant level (when cold) should be at the seam of the expansion tank.
 
GTRekky said:
Tried to attach image but didnt work. Please see the following link for an example:
Click to expand...
Looks like it was a transmission fluid warning 🤦‍♂️🤦‍♂️ Should have done my research before looking like a plonker 😂

Really appreciate your help :)

I'll top up the coolant again to that seam and monitor how much it drains over the next couple of days :)
 
Stanleysteamer said:
Do you not have access to a compression tester for diesels?
Click to expand...
I just pressure tested the cooling system and that held pressure for 20 mins with no leaks.

I do have a compression tester, how would I go about this test on the TD5? Is it as simple as pulling the glow plugs, disconnecting injector loom, then cranking with the compression tester on each cylinder??
 
GTRekky said:
I just pressure tested the cooling system and that held pressure for 20 mins with no leaks.

I do have a compression tester, how would I go about this test on the TD5? Is it as simple as pulling the glow plugs, disconnecting injector loom, then cranking with the compression tester on each cylinder??
Click to expand...
Are you still losing coolant ?
 
In my opinion, it's quite likely that your block is not completely flat and coolant is leaking out under the head gasket into the cylinders.

Im rebuilding one now with exactly this problem and using similar amounts of coolant.
 
Alpinejim said:
In my opinion, it's quite likely that your block is not completely flat and coolant is leaking out under the head gasket into the cylinders.

Im rebuilding one now with exactly this problem and using similar amounts of coolant.
Click to expand...
Thanks for the suggestion. What would cause the block to not be flat?

I don't believe the head has ever been off in the past and its not overheated. Could this happen over time due to heat cycles?

Thanks,
Ben
 
GTRekky said:
Thanks for the suggestion. What would cause the block to not be flat?

I don't believe the head has ever been off in the past and its not overheated. Could this happen over time due to heat cycles?

Thanks,
Ben
Click to expand...
If the head gasket has let some coolant through then it seems to eat up the metal in that area.
It really doesn't need much of a gap.
I was losing coolant once in this manner, I replaced the HG, drove to the south of France and back, then it started to lose coolant again.
The new HG held for 2k miles but obviously settles with heat cycles enough that coolant can leak if the block is not flat.

You could try some dye in the coolant to see if it's coming out elsewhere but it seems that it's getting into the cylinders.
 
Alpinejim said:
If the head gasket has let some coolant through then it seems to eat up the metal in that area.
It really doesn't need much of a gap.
I was losing coolant once in this manner, I replaced the HG, drove to the south of France and back, then it started to lose coolant again.
The new HG held for 2k miles but obviously settles with heat cycles enough that coolant can leak if the block is not flat.

You could try some dye in the coolant to see if it's coming out elsewhere but it seems that it's getting into the cylinders.
Click to expand...
In the old days, once you changed a head gasket you were supposed to retighten the head bolts 100 miles later. Can't help thinking it might still be a good thing to do.
But if the damage to the head or block is deeper than a thou or two it'll need more than just a HG change.
 
Stanleysteamer said:
In the old days, once you changed a head gasket you were supposed to retighten the head bolts 100 miles later. Can't help thinking it might still be a good thing to do.
But if the damage to the head or block is deeper than a thou or two it'll need more than just a HG change.
Click to expand...
How much more would you tighten them though?
 
tom1979 said:
How much more would you tighten them though?
Click to expand...
Not more...... REtighten them, i.e. loosen them first then take them back up to the proper torque that you used the first time.
One at a time in the conventional spiral order that you would normally use.
I suppose this went out with the stretchy bolts and the use of torque then angle.
 
Stanleysteamer said:
Not more...... REtighten them, i.e. loosen them first then take them back up to the proper torque that you used the first time.
One at a time in the conventional spiral order that you would normally use.
I suppose this went out with the stretchy bolts and the use of torque then angle.
Click to expand...
Yep don't think this would work with stretch bolts without replacing them.
 
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