28 replies to this topic

[Shamone]

Mentioned this last year, and there was a thread with people with similar issues, but no cure. Wondered if anyone else has had this since then and may be found a cure? With the roof off I get a petrol/oil smell in the cabin when accelerating. It doesn't happen on flat throttle, but even slight acceleration causes the smell. I was thinking exhaust and running rich, but would be surprised if this can get to the cabin when doing any kind of speed. Cheers Simon

[VIX]

I certainly had an oil smell which a catch tank failed to resolve. I now have an extended breather to the rear n/s of the car which seems to have sorted it. I believe NickB777 has the same.

[techieboy]

I get it occasionally but not to anything like the extent that NickB777 and VIX have had it. So, don't know whether Courtenay's have changed the venting arrangement in any way or whether my senses are under so much assault from the rest of the car that I don't notice it. Wonder whether Vocky's modification to the inlet manifold gasket (cut's out a hole to match the vent in the block, as per the GM build book) that he did to Joe's car also helps?

[vocky]

the GM ecotec build book shows the inlet manifold gasket should be modified, this keeps the PCV system working. The gasket does require sealant adding around the slot - as per the GM build book. otherwise it's probably best to keep the cam cover breather connected to the throttle body inlet pipe, if you have a catch tank remove the small filter and fit a pipe to the throttle body inlet pipe hopefully with some vacuum in the PCV system the smell will be less of a problem. [PCV = Positive Crankcase Ventilation]

[The Batman]

i had no oil smell while driving in mine so the modified gasket probably did the trick

[Muncher]

I have the same issue, the smell can be quite strong. Can we have a show of hands of who has modified the gasket and who has the smell?

[The Batman]

I have the same issue, the smell can be quite strong. Can we have a show of hands of who has modified the gasket and who has the smell?

did you ever remember what courtenays said the reason was?

[rik]

i haven't modified gasket, and breater pipe runs to o/s rear.. i haven't smelled even the faintest wiff of anything

[Shamone]

Looks like I'll be modifying the gasket. Will let you know if it cures the problem. Would be interested as to why Courtney don't do this.

[techieboy]

Would be interested as to why Courtney don't do this.

Yeah, I'd be interested to know why, as well. Maybe they just don't want any cack venting from the engine into the manifold and possibly clogging up the Laminova cores. Like I said, mine isn't particularly whiffy but will follow with interest, all the same.

[NickB787]

I used to have it ran the breather pipe to the rear nearside, behind the wheel with a angled cut on the tube pointing backwards, now no problem, (not supprised really I don't think the fumes can travel that fast )

[Muncher]

I've finally just spoken to Jon about this and he's refreshed my memory The vent into the intake manifold is only a secondary breather and is not really required. Jon has spoken to his mate at Lotus who has confirmed this. The reason the GM build book suggests doing this is as an OEM they cannot be seen to be breaching emissions control regulations, they have to show it done that way. Whilst doing it won't cause any harm, it will cause the laminova cores to be coated in oil and it may also require adjustment of the map to prevent detonation. That's why Courtenay don't do it.

[techieboy]

Whilst doing it won't cause any harm, it will cause the laminova cores to be coated in oil and it may also require adjustment of the map to prevent detonation. That's why Courtenay don't do it.

Sounds like justification enough for not doing it, too me.

[Shamone]

I'll be leaving mine too, although I'm starting to think mine smells more like petrol than oil. I'm going to check it's not something else like a leaking injector or something similar. I guess if it only smells when I accelerate then it must be after the fuel rail as this is pressurised regardless. I cannot imagine it's from the exhaust as I can smell it instantly on opening the throttle and regardless how fast I'm going (with the roof off).

[Muncher]

I'll be leaving mine too, although I'm starting to think mine smells more like petrol than oil.

I'm going to check it's not something else like a leaking injector or something similar. I guess if it only smells when I accelerate then it must be after the fuel rail as this is pressurised regardless. I cannot imagine it's from the exhaust as I can smell it instantly on opening the throttle and regardless how fast I'm going (with the roof off).

I'll be moving my breather to the rear of the car as I think that's more plausible as the cause of the smell. Jon said some z22se engines really like to breathe so that could be my issue.

[NickB787]

Think the rear pipe fix is the best solution I got fed up with the smell before I did the fix.

[richyroff]

Under hard work I can still smell oil in mine. Last track day in Abbeville I found oil dripping from the vent pipe in the near side rear arch. Now fitting a catch tank which will hopefully cure the problem. The above was possibly made worse by just overfilling the oil

[Exmantaa]

I did post a similar question on Z22SE for my SC conversion, but summarized: - The gasket mod (a la GM book) will make a working closed PCV system. (ventilation air/gasses are sucked in AFTER the laminova's.) GM had to do this for emission regs... - Courtenay say this is not necessary. Ventilation from valve cover will be sufficient. Oil gasses in inlet may affect tuning. (detonation) What on this crank vent hose from the valve cover? - Like normal directly on the air inlet before TB? (will contaminate the inlet tract. My used SC manifold + laminova's were covered in oil....) - Use catch can => ventilate can to air inlet? - Use catch can => ventilate can to outside? (use long vent tube, exit behind car.)

[Muncher]

Hi, Paul here's what we see to be the answer to the LM850 breather path through the inlet manifold, following a thread some time back (I think it was on Z22SE?) I contacted ### my friend at Lotus just to be doubly sure that what we Hitec and & Delta have been doing for the last 5 years or so was not a bad or the wrong thing to be doing.

Although it was a few years back when he was doing the build and test work for both LM850(2.2) and the LSJ (2.0SC) His memory and gut feeling was telling him that the breather path through the head to inlet was obviously only the secondary breather path, not the primary- the primary being the main breather. So we should not have any breather issues or problems from restricting this as the primary / main breather was still in full operation.
His view was that the build manual being produced by an OEM (original equipment manufacture) was that they have to keep with full OEM emission legislation and therefore adopt a "belt and braces" approach to emissions and keep the path open, in the same way GM could not run the primary (big) breather to atmosphere.

We both agreed that from a det (pinking) point of view- that not having the oil breath back into the inlet manifold onto the lamoinova cores was an advantage, and its this reason that we do not run the primary (big) breather back into the inlet side where it will only put oil back into the inlet.

Both the LM850 (2.2) and the LSJ (2.0) are inclined to breath you can see from this clip that the LSJ with its OE secondary breather path and an additional breather still breathes under full load http://www.youtube.c...feature=related
We have had a few owners have breather fumes get back into the car, such are the aero dynamics of the VX that engine / fuel smell can seem to get sucked back. However these "smelly cars" have been cured by running the primary (big) breather with a breather filter attached, around and along the sub to the void behind the rear wheel arch liner, where the air is not dragged back to the cabin.
My man did say that he would double check the drawings for me just to be sure and get back to me if he felt we needed to change (and he generally will ) to this time I have not heard to the contrary, but as the question has been asked again I will just double check.

Cheers Jon

[Exmantaa]

Not sure on this "primary" and "secundary" breather pipe talking: A normal working PCV system sucks the air/fumes into the manifold through a PCV valve. Fresh filtered air is entering the engine by the big hose and ventilates all fumes and water vapours from the crankcase to the inlet manifold. On big loads when the manifold routing is not enough, excessive blow bye gasses can escape through the big hose to the inlet tract before the TB. (Not sure the Z22SE actually has a real PCV valve. It looks to have just a small orifice which serves the same purpose.)