Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: terry paget on 07 November 2015, 12:51:48

Title: Can I use a 2.5 radiato on a 2.0?
Post by: terry paget on 07 November 2015, 12:51:48
he radiator on my 2.0 has a pinhole in the header tank. I have a spare good 2.5 radiator. It looks the same dimensions, only obvious differences are the upper electrical plugs - I presume I can switch these - and the 2.5 rad has a hose running from upper right to lower left, with a pump in the middle.

Can I use the 2.5 radiator on the 2.0, leaving the cross hose in place as a plug?

Alternatives are drilling out the pinhole and plugging it, and buying new radiator; first might fail and second would cost time and money. Please advise.
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: RobG on 07 November 2015, 13:56:29
2.0 exc. air con. 52463044
2.0 with air con. 52463046

2.5 auto exc. air con.  52463046
2.5/3.0 with air con. 52463050
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: Nick W on 07 November 2015, 14:05:40
What have you got to lose by trying it? If the engine hoses fit the substitute radiator, then plugging the cross-hose is easy.
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: 05omegav6 on 07 November 2015, 15:41:22
What have you got to lose by trying it? If the engine hoses fit the substitute radiator, then plugging the cross-hose is easy.
Or simply leave attached :y

Certainly no harm in trying, but the main hoses need to be a snug fit, otherwise it will be a passable temporary fix allowing time for a new rad to arrive...

Incidentally a new rad might be had for £60-70 :y
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: Nick W on 07 November 2015, 15:47:34
What have you got to lose by trying it? If the engine hoses fit the substitute radiator, then plugging the cross-hose is easy.

Certainly no harm in trying, but the main hoses need to be a snug fit, otherwise it will be a passable temporary fix allowing time for a new rad to arrive...

Incidentally a new rad might be had for £60-70 :y


Won't the main hoses be the same 32mm diameter that has been an almost universal size for decades?


Although I have to agree with the new, correct radiator for that sort of price.
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: 05omegav6 on 07 November 2015, 15:53:55
Was also concerned that the spigots might be in a slightly different place, potentially straining the hoses...

£50 delivered...

http://www.ebay.co.uk/itm/VAUXHALL-OMEGA-2-0-2-2-2-5-3-0-1994-2003-RADIATOR-BRAND-NEW-2-YEAR-WARRANTY-/281076260726?fits=Car+Make%3AVauxhall%7CModel%3AOmega&hash=item4171735f76:g:rxoAAOSwxH1UGDnG

Buy it now, and it will be on your doorstep Wednesday  :y used these guys to good effect...
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: terry paget on 07 November 2015, 20:33:17
Here's an amazing thing. I fitted a 2000 2.5 radiator, in my stick, saved as OK, bit tricky to fit because the rear hoses and pump were a bit in the way. Filled with coolant, armed engine, and this one has a crack where the other had a pinhole. Bother.

Thanks for reference, Al. Will buy one in tomorrow.
Pic follows of leaking crack in header tank.
https://www.dropbox.com/s/00dxb0j6txfugro/LEAK50%25jpg.jpg?dl=0 (https://www.dropbox.com/s/00dxb0j6txfugro/LEAK50%25jpg.jpg?dl=0)
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: terry paget on 08 November 2015, 11:44:57
The replacement radiator came for the Opel 2.5 I scrapped in July. It wasn't leaking then. Also it failed in almost the same place as the original radiator - top of LH end, on a flat bit, not cracking around the top house pipe like I have known before.  I went to bed a puzzled man.

Got up this morning, inspired - must be head gasket gone, pressurising the coolant system, blowing out of weakest point; though I thought the pressure cap should be that point. Simple check, compression test.

Checked compression; no. 1 13.5; no. 2 12; no. 3 13.5; no. 4 13.

What is going on?
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: 05omegav6 on 08 November 2015, 11:53:40
Rad tanks crack at the mould seams... pin hole eventually becomes a crack if left long enough... guess the plastic has a moulding deficiency and goes brittle over time :y
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: terry paget on 08 November 2015, 20:53:42
So the replacement radiator instantly failing in the same place as the original was coincidence. May be so. I grant my head gasket failure theory is confounded by the compression test, also by the fact that were the HG blown pressure would be released by the header cap.
I accept that constant flexing of the top hose pipe by engine rocking may eventually crack it. I can imagine no similar force to crack the flat top of the RH tank, possibly hot/cold cycling. I appreciate it failing on the top, some way down the side I would never have seen it.
I am currently awaiting delivery of clutch parts, so I shall pause my coolant loss mystery until the Clacton car is reassembled.
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: 05omegav6 on 08 November 2015, 21:47:37
Could simply be a lack of checking :-\

Coolant level warning might a worthwhile addition ;)
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: terry paget on 09 November 2015, 17:59:41
This dear old lady is not worthy of improvement. We've had it 10 years, over that time all members of the family have had it for a while. It has seen service in the last month as a builder's van (it's an estate). Its probable fate is scrapping, as one car has to go.

This radiator fault has me puzzled. I am contemplating replacing the pinhole radiator to locate the hole, then drilling it out, tapping the hole, and screwing in a plug and washer. Do you think this might work?  The plastic feels quite thick there. Or putting a washer and nut inside (I can get access via the top hose pipe).
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: terry paget on 10 November 2015, 08:01:34
Does the yellow cap on the header tank release pressure? It is labelled high pressure and has the number 140 stamped on it. I still suspect head gasket failure. I have video of the original radiator blowing out water, and gas is bubbling through the drop of water. I know this does not fit with the compression readings, but it would tally with the second radiator promptly failing in the same way.
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: terry paget on 24 November 2015, 08:19:27
This 2.0 has been parked since the 9th while I have been playing with other cars. Turned the key this morning, fired up first time. Too good to scrap. Tell me, is the compression test proof that the head gasket is OK? If so, it deserves a new radiator. My question is - could the head gasket be blown and yet the compression test shows 4 cylinders similar compression?
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: 05omegav6 on 24 November 2015, 14:13:53
This 2.0 has been parked since the 9th while I have been playing with other cars. Turned the key this morning, fired up first time. Too good to scrap. Tell me, is the compression test proof that the head gasket is OK? If so, it deserves a new radiator. My question is - could the head gasket be blown and yet the compression test shows 4 cylinders similar compression?
Don't think so on the four pot as they leak between cylinders rather than outside like the 2.5/3.0s :-\
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: terry paget on 24 November 2015, 17:21:39
My 2.2 four pot was losing coolant. Changing head gasket has cured that. This 2.0 has been losing coolant somewhere. I have found a pinhole in radiator header tank at top near top hose pipe. I changed radiator for a 2.5 radiator, which then lost coolant via a crack in almost the same place. Compression test shows all 4 cylinders about 12.5 bar. Now looks like radiator to me, easy cure. I think you are agreeing, Al. Am I right?
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: 05omegav6 on 24 November 2015, 17:28:18
Indeedy ;)
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: terry paget on 28 November 2015, 08:55:14
Am fitting new radiator. I have transferred the sensor plugs and fan from the original radiator, but find I have 2 12mm id threaded holes on radiator right hand tank which were not on the original radiator, or indeed on the 2.5 rad, How do I plug them?
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: steve6367 on 28 November 2015, 09:37:21
Am fitting new radiator. I have transferred the sensor plugs and fan from the original radiator, but find I have 2 12mm id threaded holes on radiator right hand tank which were not on the original radiator, or indeed on the 2.5 rad, How do I plug them?

Unused internal gearbox fluid cooler? If so no need to block.
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: 05omegav6 on 28 November 2015, 09:43:03
Am fitting new radiator. I have transferred the sensor plugs and fan from the original radiator, but find I have 2 12mm id threaded holes on radiator right hand tank which were not on the original radiator, or indeed on the 2.5 rad, How do I plug them?

Unused internal gearbox fluid cooler? If so no need to block.
Exactly :y
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: terry paget on 28 November 2015, 09:57:11
Thank you.
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: Nick W on 28 November 2015, 11:07:39
Stick some duct tape over the holes to keep dirt out of the cooler. Just in case you need to reuse the radiator on an automatic car.
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: 05omegav6 on 28 November 2015, 11:12:23
(http://i1277.photobucket.com/albums/y486/05omegav6/Mobile%20Uploads/DSC_0286_zps5rbr8mel.jpg)

If they are present you can leave the plastic bungs in place, just visible in pic (note only top fitting visible bit there are definitely two ;)). Alternatively for piece of mind, a suitable bolt cut short will plug the holes, but really isn't necessary. Put this way, if anything comes out of those holes, you need a new radiator ;D
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: terry paget on 29 November 2015, 06:56:57
Job done, all OK, holding coolant, no leaks. Looks like it was not head gasket after all. My thanks to all.
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: steve6367 on 29 November 2015, 09:55:38
Job done, all OK, holding coolant, no leaks. Looks like it was not head gasket after all. My thanks to all.

Good news  :y
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: sjc on 01 December 2015, 08:29:48
I've had 2 radiators failed in the same way with the tank cracking on the top hose side, I'm convinced they go brittle with age/use.

Strangely enough, I had also salvaged a spare from a car I'd scrapped and only found out it was cracked when I needed to use it. A new one was my solution too  :)
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: terry paget on 01 December 2015, 08:56:34
Thanks for that sjc. It gives me added confidence in my belief that I have cured my car. I have more radiators in my spares pile, I guess they are all junk too. At £50 for a new radiator it's obvious, at Vx prices (£160?) it's not.
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: terry paget on 04 December 2015, 13:35:23
It has made a fool of me. This morning SWMBO took it to Tesco's  I watched its departure. It was running on three, and steaming. Apparently it steamed all the way to Tesco's, other cars hung back in alarm. Coming home it ran better. I checked water level - very low. I fear head gasket has gone after all.
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: steve6367 on 05 December 2015, 08:33:18
At least thec HG is an easy job on the 4 pot  :y
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: terry paget on 10 December 2015, 17:19:19
Now here's the mystery. Compression test showed all cylinders about 12 bar; conclusion, head gasket is OK. So I change the radiator for new, all seems well for a while. Last Friday wife takes car to Tesco's, firing on 3 and leaving trail of steam behind it, on examination header tank level very low. New conclusion - HG gone after all. Car not moved since then. This morning, thought I had better run engine before cylinder fills up with water and hydraulic locks, fires immediately on all 4. What is going on?
I reckon coolant only leaks into cylinder when under pressure but engine not running, i.e. on hot stop. Left for 6 days the coolant  drains past the rings into the sump, then starts on all 4.
Any more ideas?
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: Shackeng on 10 December 2015, 17:26:54
Now here's the mystery. Compression test showed all cylinders about 12 bar; conclusion, head gasket is OK. So I change the radiator for new, all seems well for a while. Last Friday wife takes car to Tesco's, firing on 3 and leaving trail of steam behind it, on examination header tank level very low. New conclusion - HG gone after all. Car not moved since then. This morning, thought I had better run engine before cylinder fills up with water and hydraulic locks, fires immediately on all 4. What is going on?
I reckon coolant only leaks into cylinder when under pressure but engine not running, i.e. on hot stop. Left for 6 days the coolant  drains past the rings into the sump, then starts on all 4.
Any more ideas?

Given the amount lost from your earlier post, this should show up on the dipstick to confirm. :y
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: Sir Tigger KC on 10 December 2015, 17:27:17
The car dosn't like going to Tesco's, send wife to Sainsbury's instead.  :y
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: 05omegav6 on 10 December 2015, 17:32:56
Was about to ask much the same... Any evidence of water in the oil? Is it still consuming gallons of water?

Get it nice and warm then pull the plugs, start with 3 and 4 given that is most likely where the failure is... And report back. :y
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: terry paget on 10 December 2015, 20:27:21
Oil level is 1cm above max. I have warmed up and pulled plugs, all look the same as I expected, pic follows.
https://www.dropbox.com/s/syur5de2pz70duy/plugs1-4%2050%25.jpg?dl=0 (https://www.dropbox.com/s/syur5de2pz70duy/plugs1-4%2050%25.jpg?dl=0)
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: 05omegav6 on 10 December 2015, 20:54:28
If no mayo on dipstick then unlikely to be any water in the sump...

What's coolant consumption currently?

Can't see pics ??? Probably why I use photobucket ::)
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: STEMO on 10 December 2015, 21:21:38
(http://i111.photobucket.com/albums/n156/stmo987/image_3.jpeg)
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: 05omegav6 on 10 December 2015, 21:29:35
Thanks Stemo :y

That be your issue... rocker gasket and breathers this weekend :y
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: Nick W on 10 December 2015, 21:43:22
No 3 plug is getting steam-cleaned. If it isn't the headgasket, it will be something worse that will only be obvious when you lift the head.
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: 05omegav6 on 10 December 2015, 21:59:51
So what you're suggesting is that whilst the camcover is off, you might as well remove the head bolts... ;)
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: terry paget on 10 December 2015, 22:43:08
If no mayo on dipstick then unlikely to be any water in the sump...

What's coolant consumption currently?

Can't see pics ??? Probably why I use photobucket ::)
Pics show 4 identical plugs, as I expected. No mayo on dipstick but coolant level down to bottom of header tank. After fitting new radiator 29 November I drove it to Trowbridge and back (24 miles), then it was not used again until last Friday when wife went to Tesco's, steaming merrily.

Meanwhile I was completing the clutch change on the Clacton 2.5, and after sorting out the gear lever and the window winders I transferred the insurance from 2.0 to 2.5, taxed the 2.5 and thus recommisioned it. 2.5 is still running well and tomorrow will do the Oxfordshire run. Son Dan (28) returned home from Tanzania last Friday. 2.0 was to be his car, now he much prefers the 2.5. Unless it fails tomorrow he will adopt the 2.5.
Title: Re: Can I use a 2.5 radiato on a 2.0?
Post by: terry paget on 11 December 2015, 08:23:42
No 3 plug is getting steam-cleaned. If it isn't the headgasket, it will be something worse that will only be obvious when you lift the head.
You intrigue me, Nick. What are the worse options? Cracked head?
It's frustrating in that it drives perfectly sweetly, starts well (if on 3 for a while), yet still loses water with a new radiator. Its likely fate is being stripped for spares and scrapped.