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Rolf

Exhaust camshaft on its way forward due to loose setscrew

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Checking the timing belt tension for season start up, I noticed that the exhaust camshaft sprocket was not lined up with the inlet camshaft sprocket.

Removing the back cover with O-ring inside, it showed up that the setscrew in the cam was loose and the camshaft had moved forward around approx 6mm.

Pulling it back with the setscrew was easy, but now the camshaft oil seal on the front is leaking.

Who had that problem?

Has the camshaft machined into the camshaft housing on its way forward and is it therefore necessary to exchange it?

Please add picture from disassembled camshaft housing?

Who has the drawings for oil seal tools available, T000T0072A (72A), T000T0010A (10A)?

Service notes EB5, Parts list 40.07A,

Is it possible to renew in situ, any pitfalls?

My guess is this:

1. Remove timing belt at TDC, turn crank 90° backwards

2. Remove sprocket

3. Remove old front oil seal, how to pull without damaging any mating surface?

4. Clean everything

5. Locate new oil seal with special tool T000T0072A (72A)

6. Press into housing with T000T0010A (10A)

7. Reassemble, check timing marks, turn engine manually …

Parts I plan to order:

40.07A,

1 x item 15, setscrew M10, A075W1046Z

1 x item 18, O-ring, rear cover, A907E6027Z

2 x (for trial) x item 24, camshaft front oil seal, B907E6042F

2 x item 25, blanking plug, camshaft front, A907E6069F

Any help welcome!

Regards,

Rolf

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I would not attempt it in place, you need to press that seal in perfectly flat, so you really want to take the cam carrier off the car.

By all means rotate the engine 90 degrees, but remember you need to put the cam on at the same point, so that's 45 degrees of a cam sprocket. Better to stick with TDC.

Minimum parts would be

Oil O ring between the cam carrier and the head.

Timing belt (do not try and re-tension old one, not worth the risk)

front seal.

O ring for rear cover.

Some sealing chemical (Loctite 518 or search that and the post will tell you the new improved version) for the cam tower face.

cam cover gasket if you car uses them (saddle type)

Hope that helps.

Andy

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Andy,

Maybe I'm confused but I didn't follow your point about 45 degrees of a cam sprocket. I would think Rolf should do just as he listed and set the engine to TDC, remove the belt and then turn the crankshaft back 90 degrees to clear the pistons and have them all at midstroke. The camshafts stay at TDC and he is then free to do what he needs with the cam towers.

Is that what you were saying? Sorry if I missed something.

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I just meant that if he puts the belt on with the crank at 90 deg the cam shaft will need to be at 45 deg.

You can safely remove the cam shaft at TDC and safely re-install it at TDC, as long as the cam is set to approximately where it needs to be before starting to secure it back down.

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I see what you mean although the idea would be to rotate the crank forward to TDC again before you put the belt back on. Turning it back 90 degrees before working on the cam towers is a good safety precaution to take in case you happen to rotate the cam, it won't cause a valve to contact a piston.

It also helps if you need to pull a tower, you can then rotate the camshaft to the best possible positon to take as much spring pressure off the cam followers as you can before you remove the tower.

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It sounds like you have a problem with the end bolt that holds the thrust washer (see image below)

camhousing.jpg

camexploded.jpg

You do have it correct.

1) is is safest to rotate the crank back 90 deg to prevent valve or piston damage.

2) I do think it will be difficult to install a new seal correctly! ( I just did this last night on a bench)

IMG_2582.JPG

I made a seal insertion tool.

You must also be sure to only drive the seal in so that it is flush with the end of the housing. DO NOT drive the seal in all the way or it will plug the oil hole.

More pictures here http://picasaweb.google.com/lotusse/LotusEngineRebuild#5446019098294445634 click on the next several pics.

this also shows the seal removal tool.

I would remove the cam housing to do this job, and if you do REMEMBER to place magnets on the tappets to retain the shims or else they will fall all over the place and you won't know which ones go where.

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Thanks for the hints all together.

@Andy, good point with the 90/45°, turning the crank back to TDC before belt reinstallment was the plan.

Parts for a camhousing removal (hopefully not needed) will be ordered with a new cambelt.

First try will be with the camhousing not removed. The convertible gives relatively good access when passenger seat, hood and roof are dismantled.

Tapping the seal in will be done by a well experienced mechanic (not me in this case wink.gif )

@Travis

Great pictures in your album, the insertion tool pic helps a lot.

Thanks for putting it all together in your answer!

Pictures will follow maybe in a fortnight

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A little late I managed finally to make a short summary. Sometimes I miss in other threads the end of the story, so here it is for this case.

post-3590-042290900 1276690309.jpg

post-3590-071926000 1276690295.jpg

The two pictures show the access area to the cam sprocket when the hood and parts of the engine surround and the passenger seat are dismantled. Time needed for my part of work including cambelt exchange has been 8 hours.

Mechanic gave support for cambelt lay on and camshaft oil seal removal and fitting, adding another 2 hours to the job. Pulling the old front oil seal is not easy due to the limited access area, a special hook was prepared for the pulling job which needed some patience. Refitting of the new one was done with a special preparation not to damage the inner sealing area, outside seal face covered with Loctite sealing, insertion into housing with ring tool.

After being part of the exchange, I can imagine why most replies stated for not to do it in situ. Nevertheless, the convertible gives some extra access where it makes it more convenient (standing besides the car not laying over the engine) to work in that area.

A possible culprit for the loose screw (and others which wanted to leave without permission in the past) has been spotted meanwhile. The engine and gearbox mounts are worn, especially shot was the one below the exhaust manifold. This may have caused some extra loosening vibrations.

The rubber engine mountings are exchanged now, next job will be rear brakes and gearbox mounts.

Thanks for all the tips and hints provided by you fellow Esprit owners in this forum, uptime on the street is far more imho.

Now it is time to start to wear the new mounted rear tyres.

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Thanks for the update Rolf. It's always nice when someone posts the resolution to a problem, which some don't bother to do quite often.

Edited by lotus4s

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If I just want to replace the O ring on mine do I need to take the timing belt etc off and crank it 90 etc. or can I just take off the heat shield, remove the end and swap the orings out?

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If its just the o rings at the turbo end that have gone I would think the answer is 'yes'

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You can download the parts manual for your model here on the forum, since you are a full forum member, there is a page that shows the spacer and washer orientation for the heat shield.

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Section 45.05A page 439 of the 88 to 92 parts manual on TLF. Though apparently only shows chargecooler bracket.

Try section 45.05A on page 337 of the 1980-87 Turbo parts manual. Not sure on your 89 turbo bracketry...

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