Omega Owners Forum
Chat Area => General Car Chat => Topic started by: JamesV6CDX on 24 February 2014, 16:41:40
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My 3.0 (V plate) 2000 Omega V6. This car has lost coolant from day one (I've probably only done 500/800 miles in it in my ownership) and is getting increasingly worse.
It's now at the point it is emptying the header tank within 150 miles.
The compression on all of the cylinders is fine and car pulls like a train, there is no misfires. It's probably one of the best pulling V6's I've owned or driven.
The engine appears in good order and unmolested, EG plenum caps intact, everything correctly routed.
It only has a total of 98k miles. The coolant (albeit blue antifreeze) appears to have been well maintained.
All of the pipes around the back of the engine appear dry as a bone, as does the "v".
When running, I can see a very small, intermittent stream of coolant running down the block, as you look down from the top into the crank sensor, oil filter housing area, and back a git where the gearbox bellhousing bolt goes through the block and into the gearbox on this side.
I know it's not a '98 model, but it is a 3.0. I reckon the head gasket has slightly let go in the rear corner on the passenger side, as a few other members (myself included) have seen and experienced.
My understanding is that the firing rings around the pistons on the head gasket remain intact, (hence no misfires or over pressuring) but that the composite material on the gasket between the water jacket and the outside world deteriorates, hence the coolant making a bid for freedom
Any thoughts?
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Sounds a reasonable assumption. Though years ago, one of the local OOFers had a steam making V6, nothing pointed to head gasket failure other than the steam .... a compression test said all was OK. Scott eventually removed the heads to find a tiny crack in one of the fire rings ??? which was obviously the fault.
You've checked the HBV ;) ;)
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Get a.n.other header tank cap, drill and fit a tyre valve. then use that to pressurise the cooling system whilst it is not running ... far easier to find the true source of leaks when nothing is rotating or vibrating .. you can also use paper towel to wipe away traces of coolant and see if they reappear from the same spot...
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Coolant bridge also leaks down that route, had it on my 3.0 and was a perished doughty washer
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Worth popping plenum and inlet manifold out? Inspect the coolant bridge and cooler plate?
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I have the same thing happen on my 2.5. I was on the back of the passanger side head and had to take the coil pack and bracket off to get a good look.
Andy
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My 1994 2.5 V6 leaked from the rear corner of the passenger side cylinder head. It believe it had been doing it for some time before I got it because the coil pack (I refuse to call it a DIS/digital ignition system) was rusty enough that the metal plates were spreading.
It didn't appear to have any running issues. The fire rings were all intact but as soon as I lifted the heads I had 6 bracelets loosely attached to the remains of the head gaskets.
Another example of why the coolant should be flushed and replaced regularly. :y
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Coolant bridge also leaks down that route, had it on my 3.0 and was a perished doughty washer
+ 1 ;)
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Still not had time to strip right down to the cooler but I had her up on ramps today while pressurising the system
Coolant is gathering on lower right exhaust manifold nut
This is obviously higher than the head to block face, and water doesn't go uphill
Time for a proper poke about at the back with all the inlets out
It still could be from HG if its leaking higher up the gasket eg right at the back due to the 54deg angle of the v6...
No time until at least Saturday to check :(
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Maybe one of the core plugs is weeping behind the lifting eye /bracket thing :-\
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Maybe one of the core plugs is weeping behind the lifting eye /bracket thing :-\
Similar happenings on my vectra :(
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(I refuse to call it a DIS/digital ignition system)
ER, but it is a DIS....Distributorless Ignition System. :y
In this case a wasted spark DIS or on the 2.2/2.6/3.2 a coil per plug DIS.
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Get a.n.other header tank cap, drill and fit a tyre valve. then use that to pressurise the cooling system whilst it is not running ... far easier to find the true source of leaks when nothing is rotating or vibrating .. you can also use paper towel to wipe away traces of coolant and see if they reappear from the same spot...
Never heard of this before, sounds genius though. Definalty going to adapt one of my spare header tank caps incase i ever need to try this
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Get a.n.other header tank cap, drill and fit a tyre valve. then use that to pressurise the cooling system whilst it is not running ... far easier to find the true source of leaks when nothing is rotating or vibrating .. you can also use paper towel to wipe away traces of coolant and see if they reappear from the same spot...
Never heard of this before, sounds genius though. Definalty going to adapt one of my spare header tank caps incase i ever need to try this
Just make sure if you are using a compressor to turn down the pressure before hooking up. There is a pressure figure I cannot remember, but its not much.
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Get a.n.other header tank cap, drill and fit a tyre valve. then use that to pressurise the cooling system whilst it is not running ... far easier to find the true source of leaks when nothing is rotating or vibrating .. you can also use paper towel to wipe away traces of coolant and see if they reappear from the same spot...
Never heard of this before, sounds genius though. Definalty going to adapt one of my spare header tank caps incase i ever need to try this
Just make sure if you are using a compressor to turn down the pressure before hooking up. There is a pressure figure I cannot remember, but its not much.
0,5...1 bar should do it, more will blow off something ???
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(I refuse to call it a DIS/digital ignition system)
ER, but it is a DIS....Distributorless Ignition System. :y
In this case a wasted spark DIS or on the 2.2/2.6/3.2 a coil per plug DIS.
Yes.
The whole system is a digital distributorless ignition system (DIS) not just the coil pack(s).
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Cant remember how James pressurized my cooling system but he did use a mini tyre inflater thing and hooked it up to a pipe on the cooling system , didnt use the header tank :y