Excessive Oil Consumption

[Ultimatt]

Hi guys,

Can you point me to where I should be looking?

I completed a service (oil, filters, coolant etc) change about 6 weeks ago and have noticed a significant consumption of oil since. I have twice had to top up the oil as it was below the min mark.

1. I have checked for leaks and there are non apparent from the top or underneath.
2. No evidence of oil on driveway or parking spaces.
3. Cam oil seal and CAS seal were replaced 3 or so years ago.
4. I checked the oil filter and it appears securely tightened.
5. There is no evidence of oil in the coolant, or water in the oil (milky substance under filler cap).
6. There appears to be speckled, what I presume is oil, over the rear bumper surrounding the exhaust.
7. Head Gasket and assoicated gaskets were replaced less than one year ago.
8. Car drives well and exhibits no underperformance or noises.
9. There has been a more noticable smell of hot oil since completing the service.

Would appreciate your ideas and insights.

Cheers

Matt

[algirdas]

Dear Matt:

Under the circumstances you describe, I would take a good long look at your turbo. Next, does it smoke when you take your foot out of it? If so, could be exhaust guides. Does it smoke when you put your foot into it? If so, could be rings and/or intake guides (only if your car is N/A. Positive pressure of the turbo will blow oil up on the intake side guides during acceleration). Do you get a puff of blue smoke on cold start up? If so, could be guides (intake and/or exhaust).

By the way, have you pulled the plugs? What do they look like?

Just something for you to mull over until someone who knows what he is talking about chimes in.

Sincerely,

Algirdas

[Ultimatt]

Cheers Al.

Not having been behind the car when starting up or giving it boot, I don't know if it's puffing smoke. I have been keeping an eye out in the rear view mirror and wing mirrors for such signs though and nothing evident.

It is an SE so has a turbo. It was one of my suspicions but I don't know enough to know what would cause it and if there is anything I can do to rectify it myself.

Obviuosly changed the plugs for new ones at the service last month.

Matt

[RayD]

Hi Matt,
If it wasn't using oil before the service, just two things spring to mind, the type of oil used - is it known to be suitable?

And... it may not have been 'full' in the first place and your top ups have now rectified it. Did you put a measured amount in or did you keep adding oil until it reached the mark.
Cheers
Ray

[GeoffSmith]

Matt,

A good test for valve seals is to find a decent hill and to descend in a low(ish) gear at 3-4000 RPM with your foot off the throttle. If you see blue smoke in your rear view mirror when you welly it, it's probably valve stem seals.

Geoff

[Ultimatt]

Thanks guys.

I put what I thought was a measured amount in at the service, presuming US - UK conversions worked

As I have had to top up twice since then I think it maybe more though. The oil used was a 10W 40 which I beleive is the preferred option (by most)

Geoff, A shortage of decent hills around here, but I'll try and hunt one out, when time permits and try your test.

So presuming I measured correctly are we looking at two options...

1. Turbo
2. Valve Stem oil seals

Or is one of these the more likely given the symptoms?

If it were either of these, what are my options?

Cheers

[algirdas]

Dear Matt:

Neither option will be too pleasant. Rebuild the turbo and/or rebuild the head. If you are going to the extent of doing valve stem seals, you might as well make sure the head is ok overall. In other words, you will hate life if you pop the head and do the seals and once you put it all back together realize that you needed to replace the guides or it needed a valve job or a fly cut/re-surfacing.

Sincerely,

Algirdas

[Doug]

how many miles on her, Matt?

how was the oil consumption before? did it change recently or have you just now noticed it??

also you need to quantify "how much is it using" -- by that figure out how much it uses in 1000 miles. I had a mid 1990 Mitsubushi that started using lots of oil after switching it to synthetics (cure was switch it back)--the dealer showed me their standard that it was not a problem worth even checking into unless it was using greater than one quart per 1000 miles --- I'm not saying I agree -- just giving some info.

so quantify how much it is using if you can.

-D

[RayD]

Matt,

If you didn’t have an engine problem before, I can’t see how you will have one now. If the new oil is unusual in any way I’d start by changing it for a measured amount of something ordinary. Or, as Doug says, wait to see if the amount being used is normal.

It may be the oil happens to have more than it’s fair share of cleaning properties and the build up that was keeping the oil in, has been washed away allowing it to be lost through the exhaust.

Ray.

[lotuska]

Another easy check assuming that you've done everything else is to undo the oil filler cap when the engine is running and see if you can feel excessive crank case pressure...a possible affect of piston trouble.

Also could it be an issue with the pcv system (the crank case breath system) being blocked?

[Gary]

How do you check that?

[Ultimatt]

make sure the head is ok overall

When I had the head gasket done last year, the head was skimmed slightly. I did ask of the mechanic at the time if it was worth doing the Valves Stem Oil seals at the time and from what I remember, he thought not.

how many miles on her, Matt?

92,000 Doug

how was the oil consumption before? did it change recently or have you just now noticed it??

It used a bit of oil, but if I checked it every couple of months it would only have dropped to half the dip stick. I did a full service, including oil and filter change 6-7 weeks ago. I have previously used fully synth 0W 40 or 5W 40, but tried the Redline oil for this one which I believe was a 10W 40.

3 weeks after the service I had to top up by approx 2 litres, nearly at the bottom of the dipstick. 3 weeks later again, I've had to put a further litre in. This would be over only approx 1000 - 1300 miles.

I’d start by changing it for a measured amount of something ordinary

I've converted to 10W 40 Castrol Magnatec for the top ups, having used pretty much all the Redline in the original service.

Does that help any diagnosis?

[Doug]

could it be the new slippery oil then?

[RayD]

I’m repeating myself Matt, but I’d change the oil before delving into any major work especially considering the car is running OK.
Ray

[algirdas]

Dear Matt:

I have to agree with Ray. I'm sorry I misunderstood your problem. I did not pick up on the fact that all your problems started with a simple oil change. I would change back to the oil you had used long-term. I have had situations where changing the oil had triggered leaks where there were no leaks before. I see no reason why it could not result in additional oil being burned as well.

Change back to what you had used previoulsy and see what happens. Do that before you start taking anything apart.

Sincerely,

Algirdas

[Ultimatt]

Thanks all. Good advice.

The Redline stuff does not sound your run-of-the-mill 10W40 so maybe that is the culprit.

I'll use the Magnatec first as that has been recommended by a few on here and keep an eye on the levels.

Cheers. I'll let you know how it pans out and report back with the results.

Matt

[Ultimatt]

Hi All,

A bit of an update and some further guidance needed based on the results if possible.

I have been topping up using the original oil and Castrol Magnatec up till now but, having used that supply I decided to do another oil and filter service, this time reverting back to Mobil 1 - 0w 40.

I completed the oil service and topped up the system with 3.5 litres on Saturday 13th October.
I checked again this morning (Tuesday 23rd October) 10 days later,as I had been doing a few more than usual motorway miles, and the system required topping up with a further 1.5 litres of oil to bring it up to the 'max' mark.
This oil consumption (1.5 litres) was over approximately 650 miles. 500 of which on motorway and the remainder on A roads with a combination of steady and spirited driving.
I did notice under heavy accelaration / engine load that a burst of darker grey smoke was evident via the door mirror.

Therefore, taking into account that I have reverted back to the original spec of oil, from before the first service, what are the next diagnostic steps I need to take, or does someone have a pearl of a diagnosis already? It's getting pretty costly on the oil consumption at the mo.

Thanks guys. look forward to your replies.

Matt

[lotuska]

When I first bought my car in 1994 from Paul Matty I had a problem with excessive oil consumption, in fact they didn't believe me so they filled it up to the max and then wired the filler and dipstick together, and then sent me off to do 100miles.

100miles later and another 1.5 litres gone...anyway they had to strip the engine and replace the piston rings (the engine only had 30K on it). No rebore needed just de-glazed the bores. Problem solved.

You couldn't actually see any smoke, nothing on start up, or idle, or flat out acceleration, or slowing down...nothing, just a slightly black exhaust.

[Ultimatt]

Thanks for that. Any ideas what time or cost was involved at the time? I have no experience with Piston Rings.

Any other theories out there?

Matt

[Doug]

agree with the piston rings as a probable cause -- try a compression test and see what happens. check the spark plugs and see if you have crud built up on one of them = the suspect cylinder.

weigh the cost of a few litres of oil every so often against the cost of a top overhaul and the time off the road to decide when it is worth doing.