Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: Brad on 03 July 2008, 11:04:26
-
Hi,
I have recently purchased an R reg 2.5 V6 (reflection). I've had the car serviced by an independent local mechanic who also informed me that the car is in top condition.
My only concern, which may be a bit of historical motoring paranoia, concerns the water gauge. Sitting in traffic the temperature can reach 100 on the gauge, then drops just above 90, then after a while back up to 100. The journeys are your typical home-to-station types. I've monitored the water coolant overflow, which shows no sign of water being lost? However, the water in the overflow is a very slight brown.
As for the display, I've only had one 'check water coolant' but this was displayed for a brief moment.
The cars done about 87k.
Can someone give me some advice? Unfortunately, I know nothing about cars and currently nervous about driving the car.
Cheers
Brad (lambb@willis.com)
-
Thats too hot by a long shot.
Is there any sign of oil in water (oil cooler failure)?
Might be worth just flushing through a few times, they refilling with proper 50:50 mix
-
...
As for the display, I've only had one 'check water coolant' but this was displayed for a brief moment. ......
As long as the water is up to the correct mark on the header tank I wouldn't be too concerned about the 'low coolant' message, the level switches in the bottle do tend to fail.
-
I have the same motor, and get the the "coolant message" regularly :) Also it gets hot (it even smells a bit hot), but someone told me to expect that from an engine this size. I don't like it much though. Going to France this summer with this car, and frankly I'm a little bit concerned. If you guys don't hear from me for a good while, I'm in France working to save up for a new engine! ;) :-/
-
I have the same motor, and get the the "coolant message" regularly :) Also it gets hot (it even smells a bit hot), but someone told me to expect that from an engine this size. I don't like it much though. Going to France this summer with this car, and frankly I'm a little bit concerned. If you guys don't hear from me for a good while, I'm in France working to save up for a new engine! ;) :-/
What are the markings on your gauge, and how hot does it get?
-
This temperature thing for the V6 is doing my head in! There seems to be 101 different views on the subject. TB is saying that 100 degrees is way too hot and yet my owners handbook quite clearly states that this engine will reach 100 degrees at times. The main fan does not kick in until the temperature reaches around 100. Are we saying that your main fan should never be used? I felt my running temperature was too hot and rather than go through the process of flushing out the rad (I think there may have been an oil cooler failure at an earlier point in the cars life) I fitted a a new radiator. Normal cruising temperature is now around 92 Degrees but this can vary with the ambient temperature and how much load is being put on the engine. On a cool day the cruising temp can be as low as 88 but as high as 94 on a warm day. The gauges on these cars seem to be ultra sensitive. On a warm day in traffic, especially after perhaps an uphill stretch, the temp still reaches 100 when the fan cuts in and brings it down. If you stay stuck in the traffic it goes back up again and so on... Brads temps sound perfectly normal to me.
Geoff
-
mine kicks in about 97 deg. I have always found vauxhalls to run high. But that is just my own opinion mate :y normal run temp at 90 but easily up to 95 in town and still traffic. seems yours ok... well at least the ame as mine ;) and i have had no major probs :)
-
Normal is with the needle in the middle of the gauge, ie 2.5 petrol - 95degrees, each mark up or down is 2.5 degrees. At 50mph in normal traffic the engine temperture should read 95 degrees or just below - 'fact'. Most models have three fans, one engine, two aircon (some have one aircon), all three fans have two speeds, low/high. Aircon fans run as a pair at low speed with aircon on, engine fan starts at 95c, as the temp increases (the sequence does differ by model/year) the fans step up to high speed. For fans to run at high speed is unusual in the UK. Most engines do not go higher than 97.5 without a reason, 100c to high, suggest as TB flush out system 5/6 times, then refill with a 50/50 mix, check level over a number of days.
Fans speeds, relays, thermo switchs can be all tested.
regards
richard a
-
Normal is with the needle in the middle of the gauge, ie 2.5 petrol - 95degrees, each mark up or down is 2.5 degrees. At 50mph in normal traffic the engine temperture should read 95 degrees or just below - 'fact'. Most models have three fans, one engine, two aircon (some have one aircon), all three fans have two speeds, low/high. Aircon fans run as a pair at low speed with aircon on, engine fan starts at 95c, as the temp increases (the sequence does differ by model/year)the fans step up to high speed. For fans to run at high speed is unusual in the UK. Most engines do not go higher than 97.5 without a reason, 100c to high, suggest as TB flush out system 5/6 times, then refill with a 50/50 mix, check level over a number of days.
Fans speeds, relays, thermo switchs can be all tested.
regards
richard a
More confusion! If you are saying that the sequence varies by model and year surely this could account for different accounts of temperatures? Do you know what the differences are? I'm sure my main engine fan does not cut in until the temp is near a hundred - should it be coming on at a lower speed before that?
Geoff
-
Yes, however there are 'two thermostatic switches' located on the near side of the radiator below the top hose, they both have three wires. The top one is the primary switch, it controls - 1) low temp, all fans on low, 2)medium temp, only aircon fans on low 3) high temp, only engine fan on high. The secondary switch controls 1) medium temp,aircon fans on high. Send me a email and I will send you a 'fan test method'.
regards
richard a
-
Sorry, send a PM with a email address.
-
Methinks I know the problem ... :)
He's transplanted the wrong engine ... trying to move 2 tonne car with a 2.5 cc engine ??? my model aircraft had larger engines !!!! and a 2.5 V6 .. so each pot is .42 cc ?? damned "fine" engineering
(Sorry couldn't resist it !! ;D ;D ;D ;D ;D )
-
Methinks I know the problem ... :)
He's transplanted the wrong engine ... trying to move 2 tonne car with a 2.5 cc engine ??? my model aircraft had larger engines !!!! and a 2.5 V6 .. so each pot is .42 cc ?? damned "fine" engineering
(Sorry couldn't resist it !! ;D ;D ;D ;D ;D )
..there's always one.. ;)
One other point is that the marking (numbers) on the guage are completely different on facelift vs prefacelist (incl mini fl). FL's show lower numbers - I think its rubbish as they are running the same power plant.
So the conclusion is that in normal driving the needle should be around the middle of the guage regardless of what number that shows (which will be highly approximate anyway.)
-
Spot on !! All manufactures attempt to get the 'normal' running temperature in the middle position, on Omegas the fans are there help keep the engine at that temperature. :y
regards
richard a
-
Right, to clarify running temp.
Later Omegas have 80/100 markings (making midpoint 90C)
Earlier had 90/100 markings making midpoint 95C
The cruising temp should be a shade under midpoint. This should rise to a shade over midpoint in traffic before low speed fans cut in (around 92C/96C depending on gauge markings). If temp continues to rise, high speed fans should come in at around 965C/98C (depending on gauge markings).
We have seen one instance of a minifacelift MV6 running hot on the gauge, yet everything else was fine (Hotel21's car). After a lot of checks and friggin, we Tech2'd it last year, and found the instrument panel had no config on it. Putting one on instantly cured his issue - which was gauge related, rather than engine getting too hot.
-
I had similar erratic temperature readings till I did a full flush of the coolant earlier in the year.Temp now remains at a hsade under 95 (mid point on my gauge) and only every goes slightly over 95 when stood in traffic or hard driving up very steep gradients and then quickly returns to mid point.
From my experience the coolant should be regularly flushed as for the fairly small cost it is good preventive treatment.
Have also read some where that rad thermo switches do come in different temperature bands so again for the peace of mind would be worth fitting genuine new ones if you are keeping the car or really rely on it like I do.l
-
I had similar erratic temperature readings till I did a full flush of the coolant earlier in the year.Temp now remains at a hsade under 95 (mid point on my gauge) and only every goes slightly over 95 when stood in traffic or hard driving up very steep gradients and then quickly returns to mid point.
From my experience the coolant should be regularly flushed as for the fairly small cost it is good preventive treatment.
Have also read some where that rad thermo switches do come in different temperature bands so again for the peace of mind would be worth fitting genuine new ones if you are keeping the car or really rely on it like I do.l
If the coolant has been neglected, or car suffered an oil cooler failure, its not uncommon to see rad switch fail. £18 new iirc
-
I have mentioned this in a previous post but I have copied it in here again for information.
I'm sure the explanations given above are the most likely but just as an outside bet it might be worth checking that the earth lead connection at the battery is not deterorating. I had a problem (which I have also read about elsewhere) where the joint between the copper strands of the cable and the terminal clamp has broken down (no visible external signs of this). The symptoms are a high reading on the temp gauge (hovering around the red mark) when in fact the coolant temperature was nothing like this high. The temperature over read is worse in hot weather (which leads you to believe it is real) because the fans are working hard blowing air into the cabin and the rad fans may be working hard as well because of the higer ambient all of which is drawing more current, which makes the resistance in the earth lead higher if the connection is poor, which in turn makes the cable and clamp hot.
So how do you test this out? When the gauge is over reading leave the engine running and open the bonnet. If you touch the thicker (brown) earth cable close to the terminal you may well find it is too hot to touch. This in my experience is a sure sign that the connection is failing. The other way to check if the lead has deteriorated is, with the engine running measure the voltage across the battery terminals. Can't remember what it should be (13.6?V) but someone here will know for sure. If it is much lower than this try pushing the negative voltmeter probe through the insulation 3 or 4 inches away from the terminal in the thickest of the two cables and see if the voltage is any higher. There shouldn't be any significant difference in the voltage when measured at the terminal and 3-4 inches down the cable.
If it has failed replacing the cable is a bit of a pain as it follows a tortuous route around the engine to a power steering bolt iirc. Around £30 as well!
After two years of expecting the car to boil in hot weather I changed the cable and it has never had a problem in the two years since. Prior to this I changed both rad sensors, the temp sender unit, thermostat and coolant to no avail.
Jon
-
The earthing on Omega's and high temp reading, together with fan speeds were tackled a few years ago on a 'Catera' forum. The information regarding the 'fan test' was first posted by Terry Wong at 'Yahoo Catera Groups'. Also highlighted was the fact that all Omega's have the same poistion and size body earthing point, however a GLS model has less electrical items than a Elite, therefore the electrical pull on the Elite is greater, again the Catera people (Catera's were based on UK MV6) suggest fitting two or three addition earth leads to supplement the existing ie battery to body, battery to engine, body to engine, they cost a few £ but make a difference in the hot weather with the aircon on full.
regards
richard a
-
Interesting! Just to muddy the waters a bit more here's my 2pw. My gauge regularly reaches 100 in traffic (maybe it's 97 in real life) before the main rad cooling fan cuts in. With the aircon on ECO, the temp rises much more quickly than with the compressor running, presumably because the aircon fans are either off or on low speed in ECO mode.
I recently had a near-boiling experience where the main cooling fan and offside aircon fan failed and only the nearside aircon fan prevented catastrophe, cutting in way above 100 and bringing the temp back down to 100. This happened in traffic but the temp never dropped below 100 even on the motorway at 70.
Not having the time to faff too much with diagnosis, I took 2 days off work and replaced the rad, the thermostat and the transfer pipe (ok it didn't take 2 days to do the jobs but there were parts runs by bus involved!) I did all this because I was convinced the fans were only half the story. It felt like a blockage because I assumed that at 70 there would be enough air rushing through the main rad to cool it. I traced the fan failure, completely by fluke, when I pulled this fuse here and found it to be broken.
(http://img4011.photobox.co.uk/865092185ba6ac3b23512f5e9527dfdb84a81ffe9aede9138f92afbbab00ef4857c50ccd.jpg)
All was well until 3 weeks later this fuse blew again in heavy traffic with aircon on and again the temp would not drop below 100 even at motorway speed. Replaced the fuse again and it's back to normal.
So lessons learned are: 1. the fans do a hell of a lot more than I thought to maintain normal running temp and 2. I have a wiring issue that is causing this fuse to blow. Far cry from my Monza, which has a Kenlowe-controlled fan behind the rad and nowt else (granted, no aircon either!) and only needs to be doing about 40 to get enough air through the rad to keep the fan off.
By the way, has anybody ever heard fizzing under the plenum cover when the engine's hot? I suspect my thermostat housing isn't sealing properly, which is annoying because I heard it before the thermot**t change as well. I'm thinking of investing in a torque wrench and attempting the cambelt (thanks for the DVD TB!) and when I do I'll check the thermostat bolts. Only two of em so I reckon if they're not exactly right you get a bit of a leak.
Back to the original post: my gauge reads pretty much what yours does and it sounds fine, but flushing out all the old coolant can't hurt. Drain, refill with water only, run it, drain again, repeat about 6 times, refill with 50/50 mix. I had to make sure al lthe old stuff was out because I was putting red stuff in where previously it had been blue and I've heard the two don't like to mix!
-
Hello Alex, send me a PM with a email address, by return I will send the 'Fan Test', it checks most things.
regards
richard a
-
I have it, thanks Richard! Trouble is it makes my heat hurt to look at it, but I guess Omegas and electrics are always going to be scary so I should really try and learn something!
-
The earthing on Omega's and high temp reading, together with fan speeds were tackled a few years ago on a 'Catera' forum. The information regarding the 'fan test' was first posted by Terry Wong at 'Yahoo Catera Groups'. Also highlighted was the fact that all Omega's have the same poistion and size body earthing point, however a GLS model has less electrical items than a Elite, therefore the electrical pull on the Elite is greater, again the Catera people (Catera's were based on UK MV6) suggest fitting two or three addition earth leads to supplement the existing ie battery to body, battery to engine, body to engine, they cost a few £ but make a difference in the hot weather with the aircon on full.
I too had lengthy discussions with Terry and posted his fan test on the Yahoo UK Omega site. I have started a 'how to' with pictures which I will post when I have worked out the details. The point is that earthing problems can lead to an apparent overheat on the temp gauge so check and clean these up before spending time and money replacing other parts which may be OK. As for adding extra earthing wires this could be an alternative solution but surely better (and tidier) to fix the underlying problem (poor connection, deteriorating cable) than have any more clutter.
Jon
-
Hello Jon, yes I agree but when I looked below the battery and saw all the cable luggs attached to one threaded stud, it is easy to see the potential problem. With regards to the 'Fan Test' disregard the 'New Adjustable Fan Switch - Hayden 3653" that was to introduce a manual override in extreme temperatures in America. please make contact if you want a 'walk through' the test.
regards
richard a
-
Sorry Jon, yes you did on 28th May 2007 from Terry's post back in 2006, I found him to be very knowledgeable and friendly, for an American.
regards
richard a
-
Yes, however there are 'two thermostatic switches' located on the near side of the radiator below the top hose, they both have three wires. The top one is the primary switch, it controls - 1) low temp, all fans on low, 2)medium temp, only aircon fans on low 3) high temp, only engine fan on high. The secondary switch controls 1) medium temp,aircon fans on high. Send me a email and I will send you a 'fan test method'.
regards
richard a
I am now wondering if I have a problem with my fans as my cruising temperature is fine but in traffic there does not seem to be any intermediate fan cooling and the temperature on a warm day in traffic continues to rise to 98 degrees (I have the 90-100 gauge) when the main fan cuts in. If the secondary switch only controls the air conditioning fans then that is surely not going to affect engine temperature that much is it? Perhaps I have a problem with the primary switch? I would be grateful to receive your test details so have sent you a pm Richard.
Geoff
-
Sorry for the delay, 'Fan Test' sent. :y
regards
richard a
-
Many thanks for the test sheet Richard. Now I may be a bit thick here, but the sheet seems to be indicating the trip temperature for fans to come on at low speed is 212 degrees F which,by my reckoning, is 100 degrees C. Bit late then isn't it? High speed comes in at 230 degrees F i.e. 110 degrees C - very late!
As I say, probably me but could you clarify?
Thanks again
Geoff