C25XE V6 Cav

[GP123]

Hi all,

Ive had a V6 cavalier now since end of october and it had been garaged for around 17 years. I have since changed the following so far when ive had the time to do so.
Cam cover gaskets, spark plugs, leads, coilpack, fuel filter, fuel pump, oil and oil filter, inlet manifold gasket.

I know these days are really cold however when i start her up i feel theres a bit too much white smoke on the go at idle. I know white smoke can mean a variety of things inc head gasket failure but maybe someone has had a V6 which done the same at a time?

Under the oil cap seems fine and clean, no mayo that i can see and the oil that came out of her seemed like a dark brown. The coolant exp bottle i havent fully seen what is in it but theres like a brown substance under its cap? i assumed it to be rusty gunk...will get a better look at this at the weekend and take pictures.

The water pump thats driven by the aux belt i was told was needing changed as after a while you can hear a metal on metal grinding like bearing sound, i have a new one here.. but could that also be the smoke culprit?

I have heard the oil coolers give bother in these? but would that produce white smoke? Any tips or ideas on what to check etc? I have basic tools. I know i should really get someone to do the proper checks but shes not on the road yet but seens to run well. I guess i need to take it a spin to see what shes doing and how it drives.

Ive also heard fuel injectors/fuel pressure regulator?

Thanks for any help!

[Cavalier342]

When did you last change the coolant? A light brown trace under the expansion reservoir cap can be normal, as long as you have a 50/50 water/anti-freeze mix, it should be fine. They shouldn't smoke, not if everything is healthy. When you say white smoke, do you start it outside on a cold morning? As almost all petrol engine cars will do that. Does it emit any smoke on a warm day, or when the engine is warm?

I think from what I've been told, an oil cooler failure will give similar results to a blown head gasket, if that helps.

[Robsey]

White has to be water,
In these cold conditions, it takes quite a while for the exhaust to stop emitting white smoke.
Just general condensation.

What is the coolant level like in the expansion tank?
A failed gasket or a leak should cause a substantial loss of fluid.

If your water pump is scraping, then I would not run the engine until it is replaced.
At best, it will put metallic particles in the water jacket. At the very worst, it could break up or jam causing a resultant snapped drive belt.

A dirty line in the header tank probably means a poor mix that has not been changed for quite some time.

Oil in the water tends to look black and sludgy like an oil-slick.

[GP123]

Thanks for the replies men! appreciate the help.

By time i get home from work these evenings its dark and cant do very much apart from start her out in the shed. I reversed her back tonight fully outside and it doesnt seem as bad.. i dont know its maybe all in my head. Will get photos and videos on Friday/Saturday.

Can a rusted inside Cat do something like this? When i got the car first thing i went to change was the cam cover gaskets but as i started on the front bank i found out they were done! all nice and shiny under the seals all oil within the proper areas. Could it be they had to be done and a pile of oil maybe destroyed the cat at that time? I have a brand new cat here anyways, as i got a stainless steel exhaust for her front to back.. all just needs put on. Also have a new o2 sensor.

Is there any How-tos with pictures etc on how to properly do a full coolant change on this engine? as that may help too.

EDIT* forgot to mention the coolant expansion bottle seems to be the same and when warming up the car is putting out good heat also? Is HG failure linked with the car only blowing cold air all the time?

Thanks!

[GP123]

Also does anyone know the location of the o2 sensor in the engine bay? As i also have a new one of those to go in.

Thanks.

[Robsey]

Email sent.
I hope it helps.

The cats are more robust than manufacturers gave them credit for.

Although at about 25 years old, the cat could get tired anyway.

You sound a bit of a worrier just like I am.
If the car runs reasonably well, and you are not losing (or gaining) oil or water, then everything is probably fine.
It has only taken me 24 years to stop looking for problems that are not really there.

Blowing only cold air?
Check the heater bowden cable that runs into the drivers footwell.
Just above the cardboard under-dash cover. So left side of the right footwell if that makes sense. On the side of the heater assembly casing.

Sliding the hot/cold lever on the dashboard should cause a little flap control in the footwell to rock back and forth.
If the flap control does not move much, or at all, then the cable is ditatched from the back of the heater panel, or a locating latch has snapped off.

[James McGrath]

I had a problem with my V6 blowing cold air recently.
Turned out the heater matrix was gunked up and needed flushing out.
It's working right as rain now.

The coolant system on the C25XE seems to be a bit sub-optimal from what I've heard.
I've been told stories about air locks occurring and causing over heating.
Not sure if this is true or not, but I was told that the header tank isn't as high up as it should be. It should be in the same place as the rest of the Cavs (top left of engine bay) but Vauxhall couldn't fit it in there due to the uprated engine mount that occupies that space. So it was put down on the right hand side as that was the only place that it would fit.
Only thing is, it's not high enough to avoid air locks round the back of the engine.
Could be an old wives tale but thought I'd mention it.
Personally I park the car facing slightly uphill when I do coolant changes just in case.

Best way to tell if you have a faulty cat is an emissions test. I wouldn't replace it unless you have to.

[iangsi]

I think Humbucker all ways mentioned the oil breather needs cleaning regularly, I know nothing more about the V6 engine though.

[James McGrath]

Yes, that should be part of annual servicing on these engines.

Another weak point mentioned earlier is the oil heat exchanger that sits between the V of the engine.
Earlier engines has a steel one which rusted if the coolant mix was too week (should be at least 50/50 dex-cool water mix) allowing oil and water to mix and giving symptoms similar to head Gasket failure.
Later ones were better though.
If this had happened on your engine, you would notice mayonnaiseing in the header tank.
It sounds like your one just has normal age related deposits inside and is probably nothing to worry about.

[GP123]

Thanks for the email Robsey with the PDF files. Great help.

When i done the cam covers i also cleaned out the breather hoses, the bigger hose was really full of black gunky stuff Washed this all out and the wee hose was OK it was the fitting which was blocked i poked it through with a tiny screwdriver.

I think i will change this o2 sensor and see what happens there.. i have found the connection for it with 3 wires coming out of it just below my battery and seems to run down under the car.



Maybe she is grand but ill get a better look on Saturday and make a video of the start.

Hopefully get my Piper stainless exhaust fitted also..

[Robsey]

My pleasure -
There are about 15 sections in the Omega pdf, but I tried to keep information relevant.

Also, I am sure that there will be some minor differences between Cavalier C25XE and the Omega X25XE due to emissions control changes.

But hopefully give you a bit of guidance with the majority of your questions.

[GP123]

OK men so heres a video this morning of a cold start up and her sitting at 90 degrees on temp gauge.

https://youtu.be/3i81F0W9l3A

https://youtu.be/gDw36WbHsEg



This was the first wee blast i had in her since i got her in October. I can only go down my concrete lane a bit and back as shes off the road so i cant take it a good spin anywere really.

It just seemed to reach 40mph in 2nd with ease. Everything seems like normal driving wise. (forgot how comfortable these are).

Last night i noticed a few drips of water sitting at end of exhaust tailpipe. I smelt it etc and it was literally water?

Also could old petrol that was in the tank produce this?

Thanks again!

[Cavalier342]

water drops in the exhaust tailpipe are perfectly normal for petrol powered engines, it's just one of the ways the gases are expelled through the system.

[GP123]

The smoke shown in the videos is this an acceptable amount of smoke for this time of year. Its 6 degrees here today..

Also could a pile of condensation just be built up and a good run out is required?

[iangsi]

Last night i noticed a few drips of water sitting at end of exhaust tailpipe. I smelt it etc and it was literally water ? Thanks again!

If it's just water could just be condensation in the exhaust if it's been sitting for a long time needs a good long drive to dry it out.

[Robsey]

That video looks fine to me.
It is cold and wet, and your car does not get much of a "blow out" on a decent run.

I think it is just a lot of condensation that has collected, due to being stood for a while.

I can see generous whisps of steam from my exhaust when sat in traffic on a cold morning. All perfectly normal.

[GP123]

Thanks for the replies! Its quite sunny here today so i got a few runs in and out of the lane today.

I have to say these engines are quite punchy and def good power. I dont notice any problems and was doing 40 again before i knew it.

Got back in the yard and it was just at 90 or so and noticed she wasnt as smokey there was a bit but not as much!

Hopefully a good sign. However i have ordered a head gasket tester kit from eBay which should be here in a few days. So hopefully fingers crossed this is all in my head.

If she passes the test it must be OK just needs a good blast once i get timing belt kit and water pump done.

Also going to put on a 3.8 bar Fuel pressure regulator valve and send the fuel rail/injectors off to get cleaned and left like new etc.

But... If she doesnt pass the HG test then im not sure what to do next.