Is my car knackered?

Alfa Mark

Recently I have noticed that every so often a blast of white smoke comes out of my exhaust when pulling away from a stop or changing up to 2nd gear. I have also noticed my oil consumption going up a lot. Is it the head gasket? I have checked the oil cap and it's clean (no mayo). Any ideas?

Marcus.Aurelius

Sounds like head gasket to me, sounds like serious amount of water getting in from someplace

ART6

Alfa Mark wrote: »

Recently I have noticed that every so often a blast of white smoke comes out of my exhaust when pulling away from a stop or changing up to 2nd gear. I have also noticed my oil consumption going up a lot. Is it the head gasket? I have checked the oil cap and it's clean (no mayo). Any ideas?

Is it diesel or petrol? Could be several things with a petrol engine, most of them expensive. For example, worn valve stem seals, or broken or worn piston rings. If the former its fixable but usually means taking the cylinder head off. If the latter there could be damage to a cylinder bore and that would potentially mean a new block. Sometimes the bores can be re-honed, and oversized rings fitted, but I have not heard of anyone doing that for years -- someone else on the forum might know better.

Whatever the cause and engine, if it's using a lot of oil suddenly and puffing white smoke, then oil is getting into the cylinders and getting burned. That sounds more like a valve stem seal or a piston ring than a head gasket, and the fact that it's just started to happen suggests a broken oil control piston ring to me.

Whether or not your car is knackered depends on what it's worth to you compared with the cost of getting it fixed I guess. It might, for example, be old and only worth a grand at most, while repairs might cost a couple of grand (example. Not saying they will). But can you replace it for a couple of grand?

Sorry to hear of your trouble and I hope that some other forum member will be able to offer more optimistic advice:o

Marcus.Aurelius

ART6 wrote: »

Whatever the cause and engine, if it's using a lot of oil suddenly and puffing white smoke, then oil is getting into the cylinders and getting burned. That sounds more like a valve stem seal or a piston ring than a head gasket, and the fact that it's just started to happen suggests a broken oil control piston ring to me.

If it was burning oil it would be blue-ish smoke I would have thought?

siralfalot

what car is it?

does this happen when engine is hot or cold? or both?

Ferris

Have a look at the underside of your oil cap, if there is a white deposit, (looks like mayonaise) then its your head gasket.

Also leaving the radiator cap off, revving the engine and lookin for bubbles is another way of telling if the head gasket is shot, doesn't work on newer type cars tho due to them having an expansion bottle etc.

Does the car have a rough idle when cold?

Alfa Mark

It's a 2002 Renault Scenic Petrol 1.4. The white smoke isn't constant, in fact it's quite rare but I have noticed it more when the engine is hot. There is no white residue on the oil cap and I topped it up about a month ago but it has dropped to half the level now. I used to own a Nissan Primera and never had to top up the oil between services but am perhaps being paranoid as this is my first non jap car and I have heard of Renault's having lots of different problems.

Marcus.Aurelius

You heard right I think

siralfalot

Alfa Mark wrote: »

It's a 2002 Renault Scenic Petrol 1.4. The white smoke isn't constant, in fact it's quite rare but I have noticed it more when the engine is hot. There is no white residue on the oil cap and I topped it up about a month ago but it has dropped to half the level now. I used to own a Nissan Primera and never had to top up the oil between services but am perhaps being paranoid as this is my first non jap car and I have heard of Renault's having lots of different problems.

what sort of driving does the scenic get? is it all around town constantly? what sort of mileage has it done since you last topped it up with oil a month ago?

ART6

maoleary wrote: »

If it was burning oil it would be blue-ish smoke I would have thought?

Not necessarily in my experience but I wouldn't argue about it. Maybe blueish white? Possibly it could be steam if the head gasket was blown, but if it was that bad the car wouldn't run and he'd need his own water bowser alongside.

Looking at the post, the symptoms are that the smoke occurs occasionally but usually in the same circumstances. No loss of coolant and no emulsion in the oil filler cap. Steady and excessive oil consumption. I got involved with the identical problem with a Ford Sierra some years ago. It was doing exactly the same thing. I guessed valve stem seals and took off the head. The seals were shot. Easy to replace and a straightforward job if you have the tools and the skills, but not for the inexperienced or fainthearted;)

Mr.Diagnostic

In my experience, most people have great difficulty in describing the colour of any smoke that emits from their exhaust. Very often the difference in the shades can be quite subtle.


(sorry ferris, not having a go but this is worth a mention)

Ferris wrote: »

Have a look at the underside of your oil cap, if there is a white deposit, (looks like mayonaise) then its your head gasket.

A build up of white/brown sludge on the under side of the oil filler cap has no relationship to the state of the head gasket as long as the deposits are limited to the cap. If the oil in the engine is this white/brown colour then that is indicative of water/coolant in the oil which can be caused by head gasket among other things.

Maybe we should sticky this in an effort to kill one of the most prevalent motoring forum old wives tales on the internet.

Ferris

I defer to your greater knowledge sir , game ball.

Alfa Mark

Thanks for all the responses so far.
I have always been under the impression that to check the head gasket and cylinders you look at the oil condition and the oil cap and look for white smoke but you live and learn.
The oil looks to be in good condition but I'd expect that as I topped it right up about a month ago and there is no mayo or dirt of any sort on the oil cap. The auto sensor was reading full (6 bars) up to about a week ago and now it's ranging from 1 to 4. I've checked the dipstick but it is a not clear how much oil is left using this but there is oil in the engine.
The white smoke that I notice usually happens when I'm in stop start traffic when getting moving.
Do you think I should just keep a close eye on the oil levels (I do this anyway) and perhaps give the car a complete oil change and new oil filter or should I bring her to a garage for a professeinal look over/service?

ART6

If you're burning oil as the smoke suggests then it isn't likely to be the filter or a need of an oil change. I'm not familiar with your particular make of car so I can't comment on what could be wrong other than the comments I've made so far. If the oil pressure sensor is showing a low reading, then the oil is going somewhere and the smoke suggests into the combustion chambers. Here I have to accept the points made about smoke colour by others who have responded -- I'd settle for light grey, not blue or white:o
A good mechanic could test cylinder compression and rule in or out a broken oil control ring, and one who knows the marque might also know of any specific problems they are prone to. Whatever, I would strongly advise you to get a professional opinion because what is happening isn't going to do your car one bit of good.

Oh, and incidentally, in my experience leaking head gaskets usually mean coolant getting into the oil, traces of oil in the coolant, low compression on one or more cylinders, unusual noises when running and unusual performance. I have not personally ever come across one that caused significantly increased use of oil since most of the migration is the other way, from coolant to oil.

None of this is much help to you I'm afraid, so please ask for professional advice before you get yourself a real problem.

Best regards

ART6

Alfa Mark

Well just to update you all on this problem. On our way to Cork in August the engine misfired and lost power near Port Laoise. I got it to a local small garage and after a lot of analysis he organised to get it repaired by a guy who works for a Renault garage but does a few bits of free lancing. I had to get a full top end rebuild. Any way all seemed fine with the car till this weekend when driving back from Cork and the engine goes again(bad vibration, lack of power, engine warning light flashing). I drove the last 200km on what I think is 3 cylinders (I suspect I've only ever been driving with compression on 3 anyway). So I'm going to phone the garage today to see if I can get some money back as I don't see any point in repairing the car again. Does anyoe have any advice as regards where I stand with the garage who repaired it 2 months ago, if I can drive gently on 3 cylinders for the next while without destroying the car and if I can trade it in somewhere in the condition it's in?

ART6

You can't drive a car that's only firing on three cylinders without doing real damage. The non firing cylinder will be pumping fuel into the exhaust, which will lead to bangs and damaged exhaust. The lack of lubrication in the cylinder will wear it out, and the imbalance of firing will do God knows what. Actually, it's very difficult to drive a car in that condition since it's almost undriveable. Are you really sure it's not firing on one? Where the garage is concerned I'd expect them to argue that they only fixed the fault at the time, not all future faults, but having the symptoms back after such a short time poses questions. Personally I would pay for a full diagnostic check and then decide what to do from there.