Lotus Elan Central

by **paulwatkins** » Sun 18.06.2006, 08:03

Had a bit of trouble on a drive yesterday! Hoping some of you guys could point me in the right direction.
Travelling along at about 60mph, no warning lights or strange sounds to note,...........but then,
1. boost dial indicates no turbo operation at all,
2. blue smoke from the exhaust, with an oily deposit around the tail-pipe,
3. the engine is running dog-rough! Vibrating quite badly and transmitting it through the car.

Any ideas guys? A costly repair? What parts might be required? I appreciate its difficult to diagnose problems without seeing them first hand, but advice would be appreciated.

Not a mechanical expert, and not expecting to carry out the repairs myself, but would like to be armed with some knowledge before throwing myself to the mercy of the car mechanic!

by **Candles** » Sun 18.06.2006, 08:20

I would guess that a piston ring has failed and is letting oil up into one of the cylinders. Costly: Yes, requires a complete engine strip down, but I believe can be done in the car with the cylinder head and sump off.

This is only a guess from me. The way to check would be to pop a compression tester on all four cylinders and if one piston ring has failed, there will be no compression on that cylinder. If you don't have a compression tester, a quick driveway check would be to just pull all the sparkplugs and see if one is covered in oil.

It is possible that the cause is the turbo, so if all your plugs are clean and the compressions are good, that would be my next port-of-call. A quick peep into the turbo inlet (just pull off the concertina hose from the airbox, having undone the jubilee clip) might tell you if there is physical damage.

Good luck!

Candles.

by **John_W** » Sun 18.06.2006, 09:00

Candles wrote:A quick peep into the turbo inlet (just pull off the concertina hose from the airbox, having undone the jubilee clip) might tell you if there is physical damage.

Paul,
Sorry to hear of your woes. I agree with Candles on diagnosis techniques and that it's probably going to be expensive I'm afraid.

When you take the inlet pipe to the turbo off, don't be alarmed if there's a bit of oil coating the inside - this is common and is from the breather. Of course if it's swimming in oil, that's different.

good luck,
John

by **paulwatkins** » Sun 18.06.2006, 09:38

Thanks for the very prompt replies guys!
I will carry out the checks you have suggested and update this post later.
Thanks again, Paul

by **paulwatkins** » Sun 18.06.2006, 21:25

Carried out the checks as suggested and these are what I found:

1. Removed the spark plug/HT leads cover. The left hand chamber (1 and 2) was clean and dry. The right hand chamber (3 and 4) had some oily residue. See pic.
2. Removed spark plug 1. Thread and end was quite oily. Looked into cylinder - there was a little bit of oil in there.
3. Removed spark plug 2. End was covered in oil and had been blown away! See pic. Looked into cylinder and there appeared to be quite a lot of oil in there.
4. Removed spark plugs 3 and 4, and although the chamber above was oily the ends of the plugs were dry and so were the cylinders.
5. Had a look into the turbo inlet. The impeller was rotating freely and appeared to be fine. Some slight scoring on the sides of the actual blades. Is this a problem? See pic. It is not very clear, you can just make it out.

Does any of this confirm your original assessment? Is this repair something I could carry out myself? Is there a manual for this work? What parts would I require? What other works would be worth doing while I'm getting this done?

So many questions!!! Haha. Really appreciate your help guys
Paul

by **John_W** » Sun 18.06.2006, 22:52

Paul,
I think you need to test the compression, especially on cylinder no 2.

It sounds as though the other cylinders and turbo are not the problem, and the oil under the spark plug cover (although not desirable) doesn't look too bad either.

If the problem does turn out to be the rings, I hand over to others for advice on how to fix it.

John

by **Monty** » Mon 19.06.2006, 13:32

U didn`t over fill the Oil did u?

It could be a possible head gasket problem :roll:

by **Candles** » Mon 19.06.2006, 13:39

Unfortunately I agree with the others, it is a problem with either the head gasket or the piston rings. You'll have to take the head off and all sorts of other stuff. If it isn't the head gasket, it means a complete engine strip down, inspection and rebuild I'm afraid. Consider yourself very unlucky as these engines are normally bombproof! It isn't the sort of job that can be done at home as all sorts of things will need honing, grinding and machining flat.

A cheaper way might be to source a second hand engine and get a non-lotus garage to swap it over.

Candles.

by **paulwatkins** » Mon 19.06.2006, 13:40

The oil level was fine - i am positive that wasn't the problem.

Will the compression test reveal whether it is a piston ring problem, or a head gasket problem?

by **paulwatkins** » Mon 19.06.2006, 13:41

Sorry guys, meant to say that when I carried out the checks on sunday, there was a small puddle of oil on the garage floor.
Does this info help any further? Would this indicate leaning to either a piston ring problem or head gasket problem?

by **Ashaman** » Mon 19.06.2006, 18:15

Another cause could be a failed valve seal or guide. Something else to look into before a full engine tear down; but yes - a compression test is needed ;-)

The oil under the spark plug cover isn't a problem; it has just leaked there. That plug is way weird though...it kind of scares me. It looks like the tang is pretty much straightened out?!? Anyone know how could that happen?

by **paulwatkins** » Tue 20.06.2006, 19:17

Another observation! Just checking some fluid levels, and I noticed that the cooling system reservoir level had dropped considerably. I had filled it to the upper limit before going for the drive on saturday. Maybe another clue for you sleuths out there? :wink:

I've arranged for a mobile mechanic to call around this weekend to carry out the compression test as suggested. I'll keep this post updated.

Paul

by **Candles** » Tue 20.06.2006, 19:57

Well hopefully (if you can say this) the loss of coolant means that you have a head gasket problem. If you didn't know already, the headgasket separates the cylinders from oil pathways and coolant channels. If you head gasket has failed at a point next to the cylinder with the problem and broken completely, this would explain all your symptoms.

This is alot cheaper than new pistons and a re-bore, but still involves taking the head off. It may also involve having the head skimmed if it turns out to be warped (has the car ever been overheated badly?).

You friendly mechanic will confirm this hopefully with a compression test and you can set to work from there.

Candles.

by **Enright** » Tue 20.06.2006, 20:16

How much is the mobile mechanic charging?

If it's a free diagnosis then all well and good, but otherwise why not just spend £15-20 on a compression tester like one of these, and then you're left with the knowledge AND a useful tool at the end of it?

Might as well leave the plugs out anyway, it will save a bit of time.

by **paulwatkins** » Wed 21.06.2006, 08:31

Candles - I've only owned the car a few months, so I cant really comment on much of its history. However, during my drive on saturday, I was stuck in a jam for a considerable amount of time and the temp gauge did rise to about 3/4. I dont suppose this did the engine any good, especially if there was a problem somewhere...

Enright13 - Is it an easy enough job to check the compression using one of these gauges. I've not done it before - where could i find an explanation of the process?

Thanks for you advice and comments to date guys.
Paul

by **Monty** » Wed 21.06.2006, 10:54

3/4 is normal when sitting in traffic as long it doesn`t go any higher and the fans kick in to cool it down to 1/2 way

by **Candles** » Wed 21.06.2006, 13:07

Compression testers are easy: If you can change a spark plug, you can do this.

Simply remove the plugs and screw it into the cylinder to be tested. Then crank the engine and read the gauge! They should come with instructions as well.

Candles.

by **GeoffSmith** » Wed 21.06.2006, 14:52

Ashaman wrote:That plug is way weird though...it kind of scares me. It looks like the tang is pretty much straightened out?!? Anyone know how could that happen?

I agree, it looks pretty eroded to me but it's difficult to tell with the "soft focus, artistic shot"! The plug should look more like this. Perhaps you could confirm Paul.

Given the coolant situation, it's probably head or gasket and not pistons or valve seals/guides but a good test for valve seals is here: http://www.lotuselancentral.com/forum/viewtopic.php?t=6995&start=12.

Geoff

Paul, was this you by any chance?

by **paulwatkins** » Wed 21.06.2006, 15:02

Geoff,
sorry about the fuzzy picture - A little bit of handshake! The end of the spark plug doesn't look as though its eroded, it looks as though its been blown away. The end nib resembles an electrical weld.

Dont think that was me, but I do work in the Filton area at uwe.

by **GeoffSmith** » Wed 21.06.2006, 15:31

A bit like the third from bottom picture (but worse by the looks of it)?

Geoff

PS It's a small world - I'm an electronics engineer at MBDA!

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