706 replies to this topic

[The Batman]

I think it's time to face the music.. Martin unknowingly was probably running the new engine in with a dead cat. The flexi died before zandvoort so he had it replaced and the guy even said the cat needed replacing but due to time he didn't do it. Then drove to zandvoort and killed another flexi The damage is done unfortunately and it's down to bad luck so it's time to bite the bullet and open it up.

Edited by The Batman, 16 November 2015 - 08:33 PM.

[stu8v]

 

 

 

Should the oil grade not be 10-30 or 10-40?

 

Why? All that means is lower quality oil and worse cold temperature performance

 

Cheaper for a test for one,

 

As soon as we changed grade/brand its made a difference on my mates new engine.....

 

How else can you explain it going from being a user to using barely anything? Nothing else was touched.

 

As a trial its certainly cheaper than tearing down an engine!!!

 

 

Your mate had a gasket leak. Simple. it's why they make thick oil for vintage cars. Martin isn't seeing any leaks, so there's no point trying to cure external leaks with higher viscosity oils. This only helps gaps when the gaskets are cold, if it leaks when it's hot, it'll come out at exactly the same rate.

 

 

Not a "vintage" motor.

 

No oil leaks, Good compression test and leak down tests.

 

Like I say worth a punt, for a few quid IMHO

[Bargi]

I think it's time to face the music.. Martin unknowingly was probably running the new engine in with a dead cat. The flexi died before zandvoort so he had it replaced and the guy even said the cat needed replacing but due to time he didn't do it. Then drove to zandvoort and killed another flexi The damage is done unfortunately and it's down to bad luck so it's time to bite the bullet and open it up.

 

easy tiger, lets make sure all the other bits are OK first before open heart surgery

Edited by Bargi, 16 November 2015 - 10:31 PM.

[Nev]

As I (and Stu8v) have said, try a thick 60 grade oil (I would recommend mineral) and then thrash the engine for at least 1000 miles. We both know our stuff from genuine experience, rather than the speculation and guesswork by many on here. It's a cheap test and IMO likely to improve your situation considerably.

 

[smiley]

I'm on 10w40

[fezzasus]

As I (and Stu8v) have said, try a thick 60 grade oil (I would recommend mineral) and then thrash the engine for at least 1000 miles. We both know our stuff from genuine experience, rather than the speculation and guesswork by many on here. It's a cheap test and IMO likely to improve your situation considerably.

 

 

Clearly the fact that I work in the R&D department of a company responsible for developing 1/3rd of the worlds' engine lubricant means it's 'speculation and guesswork'. What people can't see here are the PMs with you asking me for oil recommendations or begging for oil analysis. 

 

The simple fact is this. Oil loss that great points at a serious problem. Higher viscosity oil, if it will work at all, is a sticking plaster at best. This is a new build engine and has unique oil loss problems. This points at a greater underlying issue.

[MartinS]

The cat was never declared dead. It was very slightly loose inside, the main concern was there may have been bits of my previous piston in it but none could be seen by camera so it was considered ok to go to Zandvoort. The car was then driven for about 20 miles after the repair and a soon as I went above 6000 revs the flexi split again. Then driven at no more than 3000 revs for the rest of the journey.

 

I work from home and have no garage locally who can/is willing assist and my mechanical skills are not like many of yours, so these things cant be checked the minute someone has an idea. I appreciate everyone help and ideas but operating on them can take me some time. Also checking oil burning requires covering some mileage and as I work from home and each evening now its dark and wet its not so easy to randomly drive enough miles to confirm whats happening with the oil levels.

 

It seems crude to me that all my oil worries are based on information given me by a dipstick that will at times have nothing showing on it all but at other times have oil on the first notch and also about a cm further up the stick. I basically get it out clean it stick it fully back in and give it a twirl and after a few of those you get an 'idea' of where it is.

Its annoying having all this grief based on such a random useless basis for information.

Martin S

 

[stu8v]

Do you have an mocal oil cooler fitted?

[vocky]

I would suggest you replace your engine side mounts with the OEM type and sell the current items, this will probably stop your exhaust from constantly breaking, they may give great vertical support but probably not as much lateral support. The other option is to fit inserts to the front and rear mounts, but I do not believe you will enjoy the extra vibration these will give.

 

As for the oil consumption, a borescope will let you know whether you have glazed or polished bores. I know the engine bottom end was run in at the Saab factory** when it was assembled and you also ran it in, but it is still possible that it has occurred. The bottom end assembly has not been taken apart since it left the factory.

 

The throttle body certainly was not damaged when it was fitted, so if there is now some damage to it you need to discuss that with the garage which removed the SC to replace the worn out PCV valve.

 

** or wherever GM build them

Edited by vocky, 17 November 2015 - 10:40 AM.

[MartinS]

The throttle body would have been damaged when fitted, as I'm afraid it was one I was offered last year and Mike and I took a picture of it then before sending it back, the seller will know this as it was apparently damaged in transit to me then. I appreciate why it was put on as it was an emergency at that time and am grateful for the seller and fitter of it as that solved a problem at that time when needed nd I can easily resolve that problem (if it is one). I am not moaning about that just saying it may be part of the overall problem with regards power fluctuations and am simply mentioning these things in these notes to give a full picture.

I agree with regards the engine mounts, they may be part of the problem with the exhaust but I've just got that back and have fitted it back on and going by the way it sounds now, I think it may well have had cracks in it when it went on as its sounds very different to how it has done since its fitting. Again, not moaning as I was incredibly grateful for it at that time and still am, and have had amazing help from the guy who sold me it. These things just happen and are getting sorted.

 

These are minor things along the way. Next step is to sort out a pressure test and look inside the piston area.

Martin S

 

Edited by MartinS, 17 November 2015 - 12:36 PM.

[Rally]

The throttle body would have been damaged when fitted, as I'm afraid it was one I was offered last year and Mike and I took a picture of it then before sending it back, 

 

So that TB ended up on your car anyway?

[techieboy]

This whole thing sounds like the misery I had with my first forged engine. That consumed oil at a prodigious rate and made the car look more like some kind of chipped diesel rep mobile. When it gave up the ghost at Silverstone and Vocky stripped it down, he found there was a slight oval bore from the rebore and the cylinders were all glazed. Some of that will probably have been down to the uber rich TMS map (from our NA days) I was running and some of it will certainly have been down to my way way way too gentle running in procedure. Safe to say I went about running it in in a totally different way on the second forged engine. Whilst I didn't give it death instantly, I didn't wait long. We gave it about 20 minutes at fast idle to bed the cams in. Then I did about 60 miles <4500rpm using as much engine braking as I could whenever slowing down. Dropped the oil (mineral). Went to semi-synth for 100'ish miles <6000rpm and dropped the oil again. Then just did what I wanted. Engine barely uses a drop this time around and with the PCV closed, never vented anything out of the breather. PCV is now open post-OBDTuner and it might have slightly increased the oil consumption but not to any kind of worrying level and certainly not to the extent that I check the oil after every track session like I used. Never been anywhere near a 0W rated oil on this car though and have only ever used 10W-40 or 10W-50 and leave the thin modern stuff to the Audi.

[Exmantaa]

@ Techie; had your diesel rep mobile any smoky evidence that time with those failing glazed bores, or was that all masked by the catalyst? Martins says there is no smoke at all from his engine...

[The Batman]

I think techie ran without a cat he had a silencer instead

[MartinS]

I did run it in fairly slowly, max of around 3500  for the first 500, then up in 1000 rev intervals every 200 miles and equally did the different oil types with a change at 500 then another at 1000.

I did all things I was guided to do. Cant believe I may have been better off just caning the thing. Ho hum.

leak down test and camera next, oh what joys await I wonder.

 

Martin S

 

[techieboy]

@ Techie; had your diesel rep mobile any smoky evidence that time with those failing glazed bores, or was that all masked by the catalyst? Martins says there is no smoke at all from his engine...

 

It was definitely visible to those following behind and occasionally in the rear view mirror. It let out a good puff of dark/black smoke when you went WOT and those following down to Le Mans said it absolutely reeked of fuel. I think at the time of that LM24 trip, I was on one of the various Piper 2.5" systems and which probably had one of their tiny cats and a small secondary silencer.

[The Batman]

Didn't you have black smoke which suggest fuel and not oil?

[techieboy]

 By the time the excess fuel and excess oil had mixed, it was probably nearing diesel by the time it was belching out of the back of the car.

[Captain Vimes]

On the mr2 forums there was lots of discussion about premature engine failure (worn bores and high oil consumption) with the early 1zz Toyota engine. The accepted explanation was that the ceramic pre-cat was prone to breaking up and the parts being pulled into the combustion chamber. Not sure how true it was but is there a chance that any bits of piston in the exhaust could have made their way back up the exhaust and into the cylinder? Leak down test would confirm..

[smiley]

I did all things I was guided to do. Cant believe I may have been better off just caning the thing. Ho hum.

 

 

I did the same as you, with a different result. Stop blaming yourself.