Help! Project TB2 - Update 6

[Omegatoy]

1) Have you done a compression test?
2) Have you put an exhaust sniffer in header tank? Needs to be eliminated.
3) Have you substituted the HBV for a known good one (I can bring one over if you don't have one)
4) When you give it a hard rev, does the temp drop at all, or just relentlessly keep rising?
5) Can the Tech2 talk to the CTS now it's been changed?

1) No - I really, really don't think its HG. Omegatoy has seen it, perhaps he can comment on HG likelyhood?
2) No - as 1)
3) No. Not sure if its the same as V6. Certainly easier to get at, and is not leaking.
4) Revving it on the driveway doesn't heat it up much, needs to be under load to be honest, that means driving it.
5) CTS not changed, looks like wiring issue. M_DTM and I have just been going through the wiring diagrams.  This needs to be resolved, but I'm not convinced this is the issue. M_DTM is less convinced though.

I dont hink its head gasket at all, diesels rely on compression to fire the mixture and if you had a gasket gone it just wouldnt fire up so sweet even when its chucked out its coolant it still fires up sweetly,  i reckon it could be the thermostat or a blockage somewhere in the system
Omegatoy

[TheBoy]

Which will turn out to have a stupidly simple solution...

I hope so....

I don't feel too bad about the rad, as Tunnie and I proved an issue with old one, though I thought I'd helped with all the rad flushing we did....  

[JamesV6CDX]

1) Have you done a compression test?
2) Have you put an exhaust sniffer in header tank? Needs to be eliminated.
3) Have you substituted the HBV for a known good one (I can bring one over if you don't have one)
4) When you give it a hard rev, does the temp drop at all, or just relentlessly keep rising?
5) Can the Tech2 talk to the CTS now it's been changed?

1) No - I really, really don't think its HG. Omegatoy has seen it, perhaps he can comment on HG likelyhood?
2) No - as 1)
3) No. Not sure if its the same as V6. Certainly easier to get at, and is not leaking.
4) Revving it on the driveway doesn't heat it up much, needs to be under load to be honest, that means driving it.
5) CTS not changed, looks like wiring issue. M_DTM and I have just been going through the wiring diagrams.  This needs to be resolved, but I'm not convinced this is the issue. M_DTM is less convinced though.

I dont hink its head gasket at all, diesels rely on compression to fire the mixture and if you had a gasket gone it just wouldnt fire up so sweet even when its chucked out its coolant it still fires up sweetly,  i reckon it could be the thermostat or a blockage somewhere in the system
Omegatoy

I totally agree mate, but.. as said... for the sake of a 5 min test... it would be something you could 100% tick off the list of suspects...

I had a Pug 405 diesel 1.9, admittedly a totally different engine... but it had a HG issue causing the cap to push out coolant, yet it ran sweet as sugar...

I DO agree it's not likely, but I also think proving exhaust gas is not present in the cooling system is a quick (hence very worthwhile) test to do

[TheBoy]

I dont hink its head gasket at all, diesels rely on compression to fire the mixture and if you had a gasket gone it just wouldnt fire up so sweet even when its chucked out its coolant it still fires up sweetly,  i reckon it could be the thermostat or a blockage somewhere in the system
Omegatoy

Exactly my understanding as well.  I have seen a diesel HG failure, and believe me, you know about it

[JamesV6CDX]

Depends on the type of car

See my post above, about Pug TD HG failure

[TheBoy]

Depends on the type of car

See my post above, about Pug TD HG failure

Running aside, if it was (over) pressurising the coolant, there would be bubbles in coolant. Lots of bubbles.

As stated, the engine seems perfect until you start putting under load...

[JamesV6CDX]

Depends on the type of car

See my post above, about Pug TD HG failure

Running aside, if it was (over) pressurising the coolant, there would be bubbles in coolant. Lots of bubbles.

As stated, the engine seems perfect until you start putting under load...

This is going to be an interesting one, whatever the outcome

I agree with everything said, about it's unlikely HG... but the one thing I've learned, is never take anything for granted on Omega's  

You must be feeling a bit down about it... I know I did, when my old 2.0GLS project refused to start whatever I did.. you start to loose all faith in the car..

But please don't - you will get there.

If at first you don't suceed...

This is only a thought... but I wonder if someone put radweld in it at some point to try and cure a small leak?

I once, (long time ago, I've learned a lot since!) stupidly put Radweld in an Omega V6... in short, it ruined the engine.. constantly over-pressuring, running too hot, blowing from the cap etc... I can only imagine it clogged up the tiny waterways..

[Matchless]

What was the old water pump like when you changed it? any bits missing from the blades?

[TheBoy]

What was the old water pump like when you changed it? any bits missing from the blades?

Old waterpump was good.

[TheBoy]

This is only a thought... but I wonder if someone put radweld in it at some point to try and cure a small leak?

I once, (long time ago, I've learned a lot since!) stupidly put Radweld in an Omega V6... in short, it ruined the engine.. constantly over-pressuring, running too hot, blowing from the cap etc... I can only imagine it clogged up the tiny waterways..

Yes, previous owner put some of that HG repair stuff in - lots of copper particles in the coolant (hardly any now due to flushing.

However, will they be any narrow waterways in engine?

[tunnie]

i still say put bleach in the coolant system.... with water. Then take it for a damn good thrashing, flush though with water and repeat again.

[Martin_1962]

Something is blocking water flow, pump could be cavitating.

Airlocks, blockages, duff pump, thermostat.

Can you try with thermostat removed and see if that fixes the boiling?

[JamesV6CDX]

Something is blocking water flow, pump could be cavitating.

Airlocks, blockages, duff pump, thermostat.

Can you try with thermostat removed and see if that fixes the boiling?

He's changed pump, and stat..

[JamesV6CDX]

This is only a thought... but I wonder if someone put radweld in it at some point to try and cure a small leak?

I once, (long time ago, I've learned a lot since!) stupidly put Radweld in an Omega V6... in short, it ruined the engine.. constantly over-pressuring, running too hot, blowing from the cap etc... I can only imagine it clogged up the tiny waterways..

Yes, previous owner put some of that HG repair stuff in - lots of copper particles in the coolant (hardly any now due to flushing.

However, will they be any narrow waterways in engine?

Ahh.. interesting...significant news...

I'll bet you a few beers in a brackley pub, it's related to the tack they've put in the engine then

Like I say.. a few years back... I killed a V6 Omega with radweld..

As a result.. I never touch the stuff.. I think it should be banned...

[Auto Addict]

I think, for what it's worth, you must have a blockage somewhere in the water channels.

With all the gunge the previous owner put in the system, this can't have helped.

I don't know about finding it though, without stripping the head.

My monies defo. on a blockage in the engine channels.

You've tried everything else, except change all the hoses.