very rought start and fail to iddle after head gasket change

[Tuga2112]

I have very recently replaced the head gasket.

things appeared to be fine when i finished, although the car seemed to be lacking power, it was running with a fairly stable iddle.
I took it to work, and made the trip fine, when at work,
i bleed the radiator again and tried to adjust the CAS by hear to get a smoother iddle, after that started the trip back,
while driving back home i didnt notice anything different for the most part of the trip, i did a fairly constant 50-60 mph on the motorway all the way
when i pulled to the exit, and gone into neutral, the engine died, after starting it up again, i noticed the noise wasnt right and it was struggling to maintain iddle.
if i rev it to 2k + the strange noise disppeared and as far as sounds, it sounds normal.
but when idling it just keeps on trying to stay alive barely and eventually dies out.
The strange noise seem to come from the top/middle of the engine. in fact, if i was to guess cilinder 2 seems like the exact source.
I took the spark plug of cilinder 2 just to be sure it was intact and it seems fine.

i just started it off to show the noise is making. and let it die off.
https://www.youtube.com/watch?v=5DzaKt5 ... e=youtu.be
the oil is between the 2 holes in the dipstick, and i bleed the radioator again, there is still a decent amount of coolant in the reservioir.
the engine felt really hot when this issue happened, and even tho the coolant was hot, i would expect it to be pressurized considering how hot the engine felt to the touch.

ordered a compressor tester off ebay which should arrive friday or monday, planning to test compression on every cilinder when it arrives and post news.

im hoping someone can help out with ideas.

since i have taken the head out already, i am pretty confident i can swap the gasket again, under the assumption the problem was overheating and breaking the new gasket as well as warping the head but id like to know about what else to look for before ordering more parts?

some notes from the facebook discussion copy pasted.
-my restart procedure included spinning the engine without petrol for a while until the oil pressure gauge needle moved up.
-after fitting the timing belt i spun the engine quite a lot of turns by hand (more than 10 full rotations), just to be 100% sure it was not going to hit the valves.
i never actually checked if it lined up back correctly tho.
i have just adjusted the cas a little further down, and the start did rev higher as well as longer before struggling.
i have also been reading this post
viewtopic.php?f=31...
checking the cas pin out, but the wiggle in mine is very minor, and same amount as prior to changing the gasket, so i dont think that wiggle could be the problem.
-one thing i forgot to mention and may be relevant, is that while driving, the car would backfire very easily so, i suspect it was running very rich.
- i have checked the water and oil to confirm if there was any mixture, but both seem fine. (seems like new head is ok?)
- when i fitted the timing belt, i lined up all the marks as per service manual with piston 1 in TDC, although i did adjust the CAS position before this happened, although it was running iddle ok after the adjustment.

any help is most appreciated.

PS> this is basically a douple post from my project thread.
I will copy the results from this discussion into there as i keep that as an history of the journey so far.

[Rambo]

That sounds like Massey Ferguson tractor starting up rather than an M100

I assume you used the correct head gasket ? I seem to remember people having problems previously by using the wrong one (turbo vs N/A has different water ports IIRC ???) Again, from memory, I think the best advice was to get the pukka Lotus one from SJS

[Tuga2112]

That sounds like Massey Ferguson tractor starting up rather than an M100

I assume you used the correct head gasket ? I seem to remember people having problems previously by using the wrong one (turbo vs N/A has different water ports IIRC ???) Again, from memory, I think the best advice was to get the pukka Lotus one from SJS

i got SJS one yes. i did read the stories you refer, and was also adviced in the forum to go safe like that. wasnt the cheapest out there but i went for the safe option knowing the job was going to be very time consuming

[HJ2]

Sad news!

I would start with checking the position of timing belt and pulleys again to see if none jumped a tooth. Check tension of the timing belt as well.
I would not rotate the CAS by hand with only ears as reference. Just follow the manual and start with the base timing procedure after you made sure position of belt and pulleys are OK.
From the headgaskets I have done (4) I remember that the CAS position did not change at all.

Keep us posted!

[lotusflasherman]

I'd start by doing the easiest thing first.
Check the base timing again using the procedure in the manual. (It's driven off the exhaust cam so no need to touch it for a cambelt change - just get the cam timing right and ignition timing will be the same, or close enough to make no difference).
Rotating 'by hand with ears is crazy' as timing is critical... dead easy to do it right with one of these ...AccuSpark-S8000-Professional-Ignition-Timing-strobe-lamp-Light
I suspect you're running with ignition advanced and its trying to run 'bouncing of the Knock Sensor' which is why it sounds like a tractor...

If that doesn't sort it it's check cambelt timing as HJ suggests, but that's more involved ...

[HJ2]

I hope Tuga did not put the center bolt of the top cam cover back
Then it's dead easy to check alignment

If it's out a tooth then setting the base timing will not work as well. That's why i would check alignment first.

[Tuga2112]

Sad news!

I would start with checking the position of timing belt and pulleys again to see if none jumped a tooth. Check tension of the timing belt as well.
I would not rotate the CAS by hand with only ears as reference. Just follow the manual and start with the base timing procedure after you made sure position of belt and pulleys are OK.
From the headgaskets I have done (4) I remember that the CAS position did not change at all.

Keep us posted!

Ive taken it apart again to check if the timing belt jumped a tooth,
turns out the spring in the tensioner pulley broke, and the belt was pretty loose, when spinning by hand slowly it would jump a tooth always.

I need to find where to get a replacement spring or alternatively buy another tensioner pulley from rockauto.
i fear the worst I am not sure how to proceed at the moment. but from the engine noise i heard, my guess is that at least cilinder 2 valves will need replacing. but from the experience when spinning the engine, I wouldnt be surprised if all valves would need replacing.
I have checked rockauto for parts and the individual prices seem reasonable, but theres 2 issues when trying to get 16 valves replaced,
1they dont have stock to do a complete rebuild.
2 when adding up the costs it scales up very quickly.

at the moment i have nearly £200 quid bill estimated from rockauto and still 3 exhaust valves short of the full set.
for an extra 75 quid i can get a full head with the bits in, i guess it all depends on a compression test but in order to get that i need to find miself either a tensioner sping (A100E6216S) or a whole tensioner pulley. (50 + vat and deliver from sjs OR 16 + vat and deliver from rockauto)

[Tuga2112]

I hope Tuga did not put the center bolt of the top cam cover back
Then it's dead easy to check alignment

If it's out a tooth then setting the base timing will not work as well. That's why i would check alignment first.

i did put that middle bolt in, so at the moment the engine mount is out again.. but its ok, i guess its all part of the learning curve.

[HJ2]

Good you checked and let’t hope it is not completely blown to Smitherines (or how do you people call that)

[dapinky]

Joao,

I would be tempted to put the old tensioner back in for now, just so you are then in a mechanical position to do a compression test (as the belt will work for now).

The compression test will help to establish if the valves are okay.

If not, then the head will need to come off again, and check all valves/piston tops for damage. It is only then that you can really work out how many valves you may need - it could be anything between 1 and 16! (SJ's are a stupid price - same as Lotus list prices). RA have enough inlets, but not exhausts - so it will depend how many you would need.

Have you seen this one - it's not that far from you and may be a way forward.

[Tuga2112]

I would be tempted to put the old tensioner back in for now, just so you are then in a mechanical position to do a compression test (as the belt will work for now).

The compression test will help to establish if the valves are okay.

i though the same... seached for the old tensioner and found it at the bottom of the bin... but no sign of the spring anywhere
ordered another tensionser from RA already even tho i found someone selling just the spring, it was a spanish website and didnt seem very trustworthy

Have you seen this one - it's not that far from you and may be a way forward.

yes, i have seen that one,

thats what i meant when i said

at the moment i have nearly £200 quid bill estimated from rockauto and still 3 exhaust valves short of the full set.
for an extra 75 quid i can get a full head with the bits in,

i was looking at rockauto page in one side and that ebay on the other. as you said on the phone, its a matter of knowing the extent of the damage in order to decide which of the 2 options to take.

i am afraid i cant do any progress now untill i get the tensioner spring issue resolved. depending on how long the RA parsel takes, i can then find out how to proceed.
its funny in a way, but as things stand. the worst case scenario (buying the full head) is the only scenario where i have a chance to make it to castle combe this year.

[dapinky]

If you are seriously trying to get to CC you *may* wish to take the head off whilst waiting for the tensioner to arrive (you will need that bit anyway)....

... perhaps it will be a 'waste' of time (and a head gasket), but maybe leaving it will simply delay the inevitable - a compression test which reveals anything less than perfection will need the head to come off anyway.

That way, if you only need 2 valves, you may be able to get them included in the same RA order as the tensioner, and thus save a couple of quid on postage (and a week of waiting for parts).

However, if time is less important, and you are resigned to not rushing the job by next Friday, then waiting isn't so much of a problem

I don't have a 'spare' tensioner at the moment otherwise I'd post it up to you as a temporary start - does anyone local have one they could 'loan' until the new one comes from USA - new or used will help

[Tuga2112]

If you are seriously trying to get to CC you *may* wish to take the head off whilst waiting for the tensioner to arrive (you will need that bit anyway)....

... perhaps it will be a 'waste' of time (and a head gasket), but maybe leaving it will simply delay the inevitable - a compression test which reveals anything less than perfection will need the head to come off anyway.

That way, if you only need 2 valves, you may be able to get them included in the same RA order as the tensioner, and thus save a couple of quid on postage (and a week of waiting for parts).

However, if time is less important, and you are resigned to not rushing the job by next Friday, then waiting isn't so much of a problem

I don't have a 'spare' tensioner at the moment otherwise I'd post it up to you as a temporary start - does anyone local have one they could 'loan' until the new one comes from USA - new or used will help

im giving up hope for CC at this point.
I have just found out bell and colvil can get me the spring by itself (2.50 + p&p and maybe vat), but its another 5-6 day delivery, because its a factory order. so it would be cheaper than RA, but not faster, and well. i have complted the RA order already so its a bit
I have called a local lotus specialist and as soon as i said "elan" they told me they dont have the part.

I would love to make it to CC, if i was desperate enough, i could canibalize the blue car for the parts as i proceed, but i am not that desperate. The compression tester kit has arrived just 2 minutes after my last reply, so it is very frustrating to be stopped by a broken spring.

if i take the head out at this point, will i be able to visually see what parts i need ? or is there a chanse some valves visually look ok but the compression test reveals theres still a problem ?

Im not particularly excited about taking the head off again, but im pretty sure some valves on cilinder 2 are broken. i just dont want to "fix it" for some valves, assemble everything again and find out afterwards i need to do it all over again.

[Tuga2112]

i have a potentially stupid question on this subject.

i just put a new head gasket, and assuming its fine, will i need another head gasket because im likely to take the head out again to fix the valves ?

[Brit-Car-Nut]

From my experiences over the last 50 years of engine rebuilding, you should get a new gasket.

When you first torque the head down, the rings around the cylinder holes and coolant/oil passages are all "crush to seal" type design and once crushed, they will not seal correctly if reused.

[Tuga2112]

From my experiences over the last 50 years of engine rebuilding, you should get a new gasket.

When you first torque the head down, the rings around the cylinder holes and coolant/oil passages are all "crush to seal" type design and once crushed, they will not seal correctly if reused.

im guessing im also gonna need new "head to intake" and "head to exhaust" gaskets no ?

that is pretty annoying considering how much the head gasket costs

[Brit-Car-Nut]

Actually, those are not "crush to seal" type gaskets, so as long as they don't tear, you can reuse them. I would probably use a spray on gasket sealer if I reused them like permatex 99MA Hi-Tack (red) not copper coat to make a better seal.

[Simon_P]

I think that if you take the cams off you can do the compression test.

Then take it to bits and work out how big the job is.

Unless you used sealent gunk on them most of the gaskets will be OK. Except for the HG which would be foolish to reuse.

Unless you suspect damage the belt and pulleys may be OK.

Second hand valves would probably be OK as they don't wear much, you'll need to lap them in though.

I'm pretty sure I have most if not all of the parts you will need, except I don't have new valves and I'm not sure if I could put my hand on the spring.

[dapinky]

Joao,

As John said (and I was trying to imply) - a new HG will be needed if you want it to work 100%......... in times gone by I have re-used them (as sometimes it is the only option to keep a car going during a journey), and even made a Head Gasket out of a piece of linoleum and a stanley knife so we could get a land Rover out of the jungle in Rwanda (it didn't last forever, but got us over the border and out of the country).

As Simon says, you can remove the cams and spin the engine (with plugs out!) without any risk of valves hitting pistons and thus do the compression test.....

...BUT.....

.... TURN IT BY HAND FOR A FEW TURNS JUST TO MAKE SURE THAT ANY VALVES WHICH ARE BADLY BENT (AND NOT CLOSING) ARE NOT GOING TO HIT THE PISTONS...

Probably worth having a visual check down the sparkplug holes first to make sure that there is no loose bits of broken valves flying around inside the compression space - although any such bits are probably somewhere between your workplace and home if they have already gone through the exhaust and dissapeared.

Taking the head off will mean that you can see any damage to the piston tops (if not too bad, they can be 'repaired' by smoothing out any gouges with a dremmel and stone - but any such imperfections can affect compression ratio if large dents, and also form 'hot-spots' during the ignition phase of the 4-stroke cycle).

As for the valves, if they are badly damaged, it will be immediately obvious (if the stem is very bent, or the valve seating face is broken, then they won't close) - but you will ideally, need to remove the cams and followers to check fully - although you will get a good idea of the state of them by rotating the camshafts and watching the valves open and close.

If the damage is less severe, then you can test the seal between valve and head by using a syringe to squirt a small amount of petrol into the inlet port of the head (and exhaust!) with the valves closed - none should leak out if there is a good sealing face. A small amount of seepage is to be expected if the valves haven't been removed since it left the factory due to wear and tear, but it should stay on the side it is put until the valve opens. You can also use WD-40 for the same test, but i always use petrol.

In a perfect world, you would need to remove all valves from the head and check the clearance between valve and valve guide, and roll them across a piece of glass (or kitchen worktop will probably be as good) - as they roll around in a circular path, any 'bend' in the shaft should be easily visible.

If it were me, I'd strip the head completely to assess what bits are worth saving and what needs replacing, then decide if it is better to buy a S/H one or repair the one I have. Either way, i'd remove all valves from the S/H head, re-lap them and refit the other bits and pieces...... (Basically, if there is no damage (or only a couple of valves) I'd repair, but if it was any more than that, I'd get the other head and keep the one to take off for spare parts in the future..... that way you can select the best 16 valves out of the 32 that you'll have, the best 16 followers, etc)

[Simon_P]

I cant play your video so please confirm
if the belt had slipped
If you realligned it before taking the video
If you reset the timing

If the belt slipped and you didnt reallign it im not sure what you are expecting -valve and ignition timing are quite important for an engine to run