Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: GrahamK on 29 September 2025, 16:27:07
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Hi all,
I've recently been re-commissioning the Omega after a year or two off the road.
Firstly it runs perfectly. However, I had noticed that it was loosing a little bit of coolant externally before I had parked her up. I did need to put a bit in when I got her going (perhaps one litre) and i ran her up to normal running temperature yesterday, on the drive, until the fans came on and then went off. All seems OK.
However, this morning I notice the header tank is creamy black and obviously has a lot of oil in there. The engine oil level has dropped about 5-10mm, but does not look like there is water in it.
The oil filler has a sheen of mayo in there, but nothing excessive and what I would expect from just an occasional brief run.
Having done a search on here, oil cooler seems a good bet, but I wonder if folks could let me know if this seems sensible considering all the things I have reported here.
Next the question of where I might get a new cooler from? There are not too many, if any available that I have yet found. I take it the part number is the same on all the V engines?
I have a spare engine that was running. Is it a crazy idea to refit a used one?
Does anyone have a oil cooler on the shelf that they didn't end up using?
Regards,
Graham.
p.s. Car is 2003 2.6
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Hi mate,
I don't really know about the troubleshooting of this particular case. But I can give you some info about the oil cooler.
I replaced mine (preventive move) by a stainless steel one from ACS (Advanced Cooling System), which is Ukrainian supplier for a lot of Opel/Vauxhall parts.
https://acsparts.biz/en/maslookholodzhuvach-90412391-opel-saab.-nerzhaviiucha-stal/
The part is 113€, costs near 150€ after all customs and taxes.
It comes with both new o-rings. Then you need 4 new bi-material rings and 4 new metal rings for the 4 banjo bolts of the cooler itself and the cooling bridge.
My genuine one is still like new but it's the aluminum one, so I don't want to propose it to you :D it could fail at anytime
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Thank you Valentin.
Much appreciated. It looks different to what I expect. I thought they were flat (a bit like an air cleaner element). I've not seem one, just photos.
Graham.
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The original one is flat
(https://cdn-product-images.revolutionparts.io/assets/d163e09e1523eb87b7b14f5b35648e7b.webp)
If you look on the 3rd picture on ACS website, the shape is a bit square for the cooler to fit correctly in the block :y
You can take a look at my topic here https://www.omegaowners.com/forum/index.php?topic=151703.msg2058124#msg2058124 but it seems the pictures are gone :-\ ;(
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Thank you again, that explains it perfectly.
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nothing wrong with fitting a used one in my opinion.virtually all omegas will be fitted with a used cooler ! same as any other used car and i beleive all the later coolers were stainless anyway ?
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Of course, but Graham's Omega is a later one, assumed with a stainless steel one, and if it's broken it means any other later one can do the same because the part has maybe some weakness from its thin design.
Regarding the amount of work to change it, better to change it by a model made with a strong thick tube, and don't come back to it in 5 years :y
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I think most were stainless, only very early ones weren't
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The one removed from my 96 is aluminium :y
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What are OOF members doing about replacement washers for all the pipes going to and around the cooler?
I’m guessing they’re discontinued at Peugeot, I mean Vauxhall?
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A dowty washer is a dowty washer surely :-\
Find a decent plumbing supplier and take an old one along with you ;)
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Timing is everything and I do need to get the old girl back on the road, so waiting for a delivery from Ukraine is not ideal. I have a spare engine and I'm going to have a practise by removing the oil cooler in that one and replacing mine. Mine is a late car, so should have a S/S cooler, but I don't know if the coolant has been kept in good nick or not. I will have a look at flushing agents to try and remove as much oil as possible. Thank you for confirming that some are Dowty washers, but I'll replace like for like, depending what I find.
Cheers all.
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A dowty washer is a dowty washer surely :-\
Find a decent plumbing supplier and take an old one along with you ;)
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Fair comment.
I’d always like the correct Vauxhall part in these circs.
But as mentioned might not be available so may have to do that.
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Ps.. though I’ve never had to do this job I often look at those two unions above the oil filter and they just don’t look like they’d come out 🤣🤣
Anyone ever had issues with them? I suppose absolute worst case scenario you’d end up chopping the pipe above the nut and getting a 6 sided socket on it. Just wondering if anyone ever had issue?
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Unbolt the filter housing. It's a single hollow bolt holding it to the block :y
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It’s cool DG cos I’ve already done the filter conversion.
Was just curious about any issues anyone ever experienced.
I don’t need to do this job. I’m just bi-curious 🥰
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Had heard >:D
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🤣
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Ps.. though I’ve never had to do this job I often look at those two unions above the oil filter and they just don’t look like they’d come out 🤣🤣
Anyone ever had issues with them? I suppose absolute worst case scenario you’d end up chopping the pipe above the nut and getting a 6 sided socket on it. Just wondering if anyone ever had issue?
As per above, filter off,, crows foot spanner, tighten slightly, then undo.
Never had an issue to date with them. :y (probably done many tens of them over the years, including Opti's whilst it was on his drive!)
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Great to know, thanks Mark 👍👍👍
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A used, stainless cooler, is likely to be fine. You'll need to source dowty seals, coolant bridge seals, union-to-cooler seals, grey RTV, cooler-to-plate o-rings, oil filter housing seal etc. But, a stainless, used cooler will be fine.
The old style coolers (which corrode) have protrusions on the top of the cooler radiator - whereas the stainless ones are completely flat on the top edge.
Here is the old stlye, known to corrode:
(http://images.omegaowners.com/images/guides/V6_Oil_Cooler/V6OC8.jpg)
Here is the newer, stainless type, flat on top:
(https://i.ibb.co/dwBGT6wL/new-style.jpg)
And, food for thought - I am currently in discussion with a European firm, about a bulk buy of these:
(https://i.ibb.co/Y76zyyMS/IMG-1763.jpg)
Ultimately it's almost impossible to get a new, original cooler these days (or they are astronomically priced)... so worth at least exploring potential other options / viable alternatives :y