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Mike6

Loud ticking noise coming from top of engine

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Thanks Travis. Will have another go tomorrow. Didn't want to overtighten the rubber washer on the guage but still go a reading from the Mondeo

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Did you have the throttle fully open when you tried to get a reading? If not, the pressures will be lower as you are starting with a vacuum in the cylinder.


S4 Elan, Elan +2S, Federal-spec, World Championship Edition S2 Esprit #42, S1 Elise, Excel SE

 

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Did the test again by the book ie fully charged battery, engine at operating temperature, fuel and current isolated, all plugs out, throttle fully open and clutch depressed and still getting zero. Tried it again on the Mondeo (same plug thread) and getting readings. Had a look at the compression guage and the first making is 25 psi so perhaps not getting much compression on any cylinders. Just cannot see that I am doing anything wrong unless there is some reason why the Am-Tech tester will not work on a Lotus.

Now certain that the noise is coming from under the top cam cover so guess the next step is to take this cover off and have a look around. Might even get carried away and end up pulling the head to see what is going on and then do a top end overhaul. There certainly seem a lot of oil inside cylinder 4 so could be new rings required.

Car is 20 odd years old , I have now knowledge of mileage and there is no evidence that any overhaul has been carried out

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Won't run at 25psi.

Try oil on the o-ring of the compression tester, or try a leakdown tester.

You can also check your valve clearances just by taking off the cam covers and turning the crank (especially now that you have the plugs out)


Travis

Vulcan Grey 89SE

My Lotus Photo and Projects Album

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Mike, I'm having a tough time with this. You have an indeterminate tap that turned up out of nowhere and you've failed to identify, and now you're thinking of pulling the head? At least get someone with some Lotus experience to glance at it first! And in the meantime, borrow another compression tester.


British Ambassador to Florida, New York, Denmark and Newfoundland.  And Sweden.

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Just feeling a bit depressed but Sparky you are as always correct. Will try and get hold of another comprssion tester and in the meantime just pull the cam cover to see what is going on.

Problem for me is that I don't know anyone with Lotus experience in the area and don't want to drive the car as the noise seems to be getting louder.

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Mike, you've 5 specialists within 30 miles, a loud ticking doesn't sound fatal so there's no excuse to take it to one. If you're that worried, you'd not be running it up to temp today or you could use a recovery company.


88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

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Mike first and fore most its just an engine, nothing magical just it has some expensive parts but its still suck squeeze bang blow ,start of checking all the basics ,if you have home some sort of home start breakdown service why not call them ,the guy may just point you in the right direction saving you money or confirming something much worse and you then can consider your options.Some thing along the lines of ,"i just went to go out and i have a loud ticking noise can you send someone to havbe a look?",most breakdown companies will send out a guy and have a look see,then if its in need of help can transport the car to a garage .

Nick s4s


Simplest things first.

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???? Where are you based,, surley one of us who has experience and builds these engines can get across and help...

Dave..

Edited by CHANGES

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Hi Dave, I live in East Grinstead, West Sussex (near Crawley and Gatwick Airport). A reward awaits anyone who could spare a little time.

Today I decided to remove the top cam cover. Instinct tells me that these valves are inlet ones and the book states a clearance of between 0.13 to 0.18mm. My smallest feeler guage starts at 0.10mm but on only 4 of the eight could I get the feeler guage to push in and it was tight bar one which was an easier fit. The other 4 had near enough nil clearance although you could just rotate the cam followers by fingertip which must mean a tiny air gap. These readings were repeated a number of times just to be sure on a cold engine.

This gets me thinking that on a hot engine and taking into account expansion will the valves be closing completely and could this explain the lack of compression.

However I am not sure this explains the noise nor why it should have gone so quickly. Logic suggests clearances can get larger so perhaps a previous owner/garage cocked up and lack of mileage meant nothing was noticed for some time.

I think the next step is to pull the other cam cover and check the exhaust clearances. However any other thoughts/views are always welcomed

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Hi Mike

Just a bit far for me, shame i would love to get my teeth into this little problem, The clearences sound fine they will seem tight because of the oil. if you can rotate the follower then its probably ok. I Know its awkward, but rotate all followers and have a good look for any tell tale signs... Then move onto the exhaust side and do the same...There is always the possibily that the exhaust valve guides have worn and a carbon build up on a valve stem may be causing it to be slugish, this will have the effect of a noisy tappet when running but ok when checked....The stethoscope is really good at narrowing the area down in situations like this...without being one on one with it, it is just speculative guess work, let us know if anything on the exhaust side iooks ify..

Dave.L

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Mike,

How were you turning the cam to be able to take the clearance measurements and are you sure you were measuring correctly? If so it sounds like your clearances are way below spec on several of them.

The clearances will tighten up with use which is why you want to shim to the high end of the range when adjusting the clearances.


1995 S4s

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Dave, I think you win top prize.

I purchased a new set of feeler guages to remeasure the inlet valve clearances and they measure from 0.05mm to 0.13mm. It took ages and multiple checks to come up with exact readings but they are clearly well under the book figures which must be having some effect on engine running.

HOWEVER, when I lifted the cover from the exhaust cams I immediately noticed that one of the cam followers had completely broken up and the valve spring etc was clearly visible. In fact the noise was the overhead cam directly striking the valve top and spring. From a cursory examination no damage appears to have been sustained - luckily I have probably only covered a few miles since noticing the noise. The sides of the overhead cam toe have been bashed about a bit but the part that strikes the cam follower seems ok. I am not sure where all the cam follower has gone but there are bits of swarf in the well.

A terrible thought has just come over me. Any swarf is likely to have found its way back into the sump and possible the engine although I would hope the filter would have pcked up most of it.

I guess the next step is to remove the cams completely and reasess before deciding what to do next. But with my luck it will be much more extensive than simply replacing a cam follower.

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Good find. Never seen anyone mention this happening in all the time this forum has been running.

I guess your looking at cam carrier off at the very least to give everything a good clean and assess from there.

I'd give the return gallery a flush back to the sump to make sure there's no crap in there and then maybe whip off the sump to give it a good wash and ensure no crap is left floating about in there.

Post some pics, I'd be interested to see.


Chunky Lover

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Jeeez. I'd have thought a screwdriver to the ear would have isolated that immediately.


British Ambassador to Florida, New York, Denmark and Newfoundland.  And Sweden.

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Mike, well done, this is what the forum is about, sharing individual knowledge to assist others....

Next step....Remove the cam carriers..... Both of them... be aware of the shims under the followers....some will stick in the follower and some on the valve, some may drop onto the head....if you have bar magnet as the manual surgeststhis will help a little ......you will then find 95%+ of the bits sitting in the head next to the valves in the residue oil... The bits wont be totally vissible to you so first thing is to get small very strong magnet and use it to seach all around the head...The head is alloy so it will be easy to do this.....Finally at each end of the head you will see an opening where the oil goes down to the sump.... use the magnet as far down there as possible ...BUT DONT LOSE IT....The snap-on telescopic type or similar is perfect for this..

Any bits that have gone into the sump, will be stopped by the strainer or filter..... if you want to be extra careful , after you have drained the sump leave the plug out and poor 1/2 a gallon of thin flushing oil down the gallery holes previous mentioned....then whip the sump off and clean out. ...this will be more than sufficent to cover this problem ..... An engine rebuild is not necessary....shoving a magnet up the drain hole has little effect and gets stuck to the strainer.!!!!

Purchase a set of steel forged cam followers from 'BURTON' Great quality and not to pricey , disgard all your old ones , if one has gone the rest will follow.... personally i never fit standard followers for this very reason i have seen a few like this and you are lucky. i have seen them jam the valve open and very expensive job follows.!!!!!!!

The next bit is reasemble and the shimming . This can be a pain if you are not used to it..... After reading this, this far and you still want to undertake the work i can talk you through the process ...

let me know what your thoughts are...

Dave

PS Did any one go with the each way bet on this being the fault.......

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I suppose in a way it did but noise seemed to be coming from the top cam cover rather than the exhaust side. I plan to strip it down but before making a decision as to exactly what needs replacing, bring the parts along to the next Brands Hatch meet and get peoples views. Has a date been fixed for the next meet.

Will take photos and post up.

Thanks again for all the help

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Mike, I forgot to mention i have spare cam shaft and cam carrier to suit you engine if the others are damaged...

Dave

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actually, not to be a downer...

But the oil path is sump ->pump->cooler->filter... :(

That means the debris could be in the oil cooler! It will need to be thoroughly cleaned or replaced!

Sorry to see the follower broke, I hadn't heard of too many braking either (except that the iron ones can't take higher revs like the new lighter steel ones.

I bought my set of steel cam followers from JAE in the states for $26each. They do require a thicker shim though.

I think they came from Arrow Precision http://www.arrowprecision.co.uk/followers_stock.php

They are EN24 chromoly and nitride hardened.


Travis

Vulcan Grey 89SE

My Lotus Photo and Projects Album

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Purchase a set of steel forged cam followers from 'BURTON'

A bit off topic; the 4 cylinder 9xx followers are dimensionally the same as the Lotus Ford Twin Cam then? :)

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yes they are

"Lotus Twink and 9XX tappets are dimensionally interchangeable, and the race tappets exceeded the 910 spec, so we used them. The only notable difference is the thickness of the tappet (head wall plus the internal boss). The shims had to be re-done for the new tappets, but no big deal."

Since I had to replace all of my shims, and didn't know which shims to order (using the old shims for measurements wouldn't have worked...) I ended up making dummy shims out of cast iron that I could machine easily and precisely. Then I got my measurements and ordered all the new shims to the correct thicknesses.

IMG_2652.JPG

Edited by Vulcan Grey

Travis

Vulcan Grey 89SE

My Lotus Photo and Projects Album

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You are right Travis, but in my experience when the cam follower goes down , the bits are quite large and any that get in the sump stop at the strainer.. what gets past the strainer has already gone though and will be small enough to have gone all the way to the filter. . The oil pump won't enjoy any bits passing through but it won't kill it . and is easy to recon if pressure suffers, but unlikely too....

However on a major engine failure i would recomend the cooler pipes pulled though to cleaned and coolers replaced as per the manual..

I have seen several of these followers brake on Esprit's and Excel's and some had not been driven hard... i personally feel they are a week point and should be checked if not replaced with steel ... I have found the failure seems to start when they stop rotating , The pic's you posted on page 1 had the tell tale signs of not rotating, i have seen those exact marks on failed and failing followers.....

On the shim point...

many engine that have been rebuilt, the shims have been ground to thickness, then fitted, These shims wear, I have had some with a 5-7 thou recess worn from the valve stem. The shims are only case hardened so once ground will wear...so... do as Travis has advised or re-harden before fitting . this is a simple thing which is so often over looked...

Dave

Edited by CHANGES

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what's the going rate for a new manifold? mine's going tappety tap now. Pretty sure it is the manifold, checked for loose hoses, none visible, listened while wifey revved it and it sounds like a slapping noise from the nearside rear wheel....

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If it's the manifold, the parts will set you back around £700 (manifold, studs, nuts, tablocks, gaskets). It's often an engine out job, but I've been lucky and managed the last two insitu. Labour, therefore, can be expensive.


British Ambassador to Florida, New York, Denmark and Newfoundland.  And Sweden.

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