Timing chain too loose?

Mr.G

Club Member
I removed the rocker cover to adjust my valves and noticed there was quite a bit of movement in the timing chain, in fact when I touched the chain by hand it actually can reach and touch the cylinder head.

Here is a short video illustrating this.. Is it normal??:eek:

http://www.cman.info/timingchain.AVI

Thanks for viewing.
 

SKiddell

Well-Known Forum User
The side you are demonstrating is the tension side, straight vertical drop to the crank sprocket. Under normal engine running conditions, this will be tight as it is "pulled" by the crank, but don't forget that the chain tensioner (other side) is oil pressurised and when pressure drops (engine off) the chain will lose some tension. To demontrate get a socket on the crank and inch it around, (clockwise facing the engine)-- try the chain tension again,

Have you at any time taken the cam sprocket off?
The reason I ask is that the most common reason for cam chain issues is folks taking off or moving the cam sprocket and failing to sprag the tensioner --- tensioner pops out and hey presto either you cant get the sproket back on or the chain is very very slack.
 

Mr.G

Club Member
Thanks for the info Steve.

I haven't taken the cam sproket off before, this engine is fairly new to me and perhaps the previous owner may have. For future reference how would you sprag the tensioner? Would the piece of wooden wedge shaped block to stop the chain falling into the engine also act as the sprag tensioner?

I will have to wait till Tuesday before I can turn the crank as i don't have a 27mm socket :( saying that I may try and crank it from the starter motor and see if the tension improves at all.
 

Mr.G

Club Member
Things have gone from bad to worse. :unsure:

I turned the engine from the crankshaft and the chain did go from loose to to taut - however closer inspection found a few nasties.

Timing chain guides look worn:

122989963.jpg


and there are marks on the inside of the valve cover:

122991969.jpg


Am I looking at fitting a completly new timing chain kit here?:eek:
 

Albrecht

Well-Known Forum User
George,

I don't like the look of that at all. Are those metal shavings I see in the first photo? :eek:

Can you tell us more about the history of this engine, and what you have been doing to it lately ( if anything )? Have you had the front cover off lately? How about studs / bolts that fix near the front cover area - have you changed / moved anything around there recently?

I think this needs investigating further before you run the engine again.........

Tell us more background info please.
 

Mr.G

Club Member
Hi Albrecht,

Unfortuantely I don't know much about this engine at all, it's an L28ET and was installed in March this year by a guy in the Netherlands. He told me that the engine was in good condition. All of this was based on trust as he told me that he had taken the valve cover off and the oil pan and checked the engine for wear and there wasnt any...! :rolleyes:

I havent driven the car much at all since March of this year as a lot wasnt done quite correctly when it was installed - the NA ECU is running a turbo engine - he was supposed to install it with a 280ZX Turbo Loom and Turbo ECU and Turbo Dizzy but he never manged to get it to spark so he stuck with my original NA ECU and NA Loom (my car had EFI).

The front cover hasnt been taken off by me, but I did have to change the water pump when I returned to England as it broke on the way home.

By the time I reached home the engine was blowing heavily from the intake and exhaust manifold (none of the bolts were properly tightened) and subsequently I have removed the intake and exhaust manifold and I have fitted a new gasket and now I need to refit everything back.
 
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Albrecht

Well-Known Forum User
Mr G,

I don't want to make this sound overly dramatic, but I think ( if it was my engine ) I'd investigate this fully now before going much further. Far better to get to the bottom of it before the nicer weather comes and you want to use the car..........

To be honest, looking at the pictures I'd say that the 'tight side' chain guide needs to be replaced as a matter of course. And once you have the front cover and everything else off the front of the engine, you might as well take the opportunity to replace the chain and all the tensioning components. Cost is very little considering the potential consequences of ignoring it.

I'd also have to say that the photos show evidence of a possibly high mileage engine that might need some refreshing. Once again - better investigated now and understood / rectified before the Spring.

I'd like to take a look at this in person seeing as I am so local to you, but I'm afraid I'm off to Japan on Wednesday and won't be back for a couple of weeks. I'd be happy to come over and have a look after I return though......

:(
 

Mr.G

Club Member
Thank you Albrecht for the amazing offer, I could do with the benefit of your great knowledge, please let me know when you are free. Have a safe trip to Japan and see you soon! :)
 

Albrecht

Well-Known Forum User
Mr G,

Er, thanks for the compliment - but this is not exactly rocket science.....

I'll be back in the UK around 10th January I think, so let's get our heads together over a PM or two and see if we can work out a day and time for a closer look at your engine.

I think you need to take out your radiator and remove your timing cover in the meantime........
 

adrianfr

Well-Known Forum User
That looks nasty George, that needs sorting before you drive it again, nice of Alan to come and look at it for you. A few months ago I was working on Suzy Chairs 260, it had not been run for many years but I got it going ok, I noticed the water pump was leaking and somebody knew about it as the long 6mm bolt that goes through the pump and into the block was broken off so I had to take off the front cover to drill the bolt out. Once the cover was off I could see a new problem, the chain tensioner had come right out of its housing and was jammed up into the chain. Even though the engine ran ok it was only minutes away from disaster had I not had to do the water pump.
Why did you have the engine fitted in the Netherlands, just passing through?
Happy New Year, Adrian
 

Mr.G

Club Member
Thanks Adrian for the input.

No I wasnt just passing through the Netherlands I went with the intention of having the engine supplied and fitted.

I wish i new the little I know now about engines then, going on someone elses trust (who is based in another country) isnt always the best policy. Well you live and learn.

I suspect it could be the tensioner that has gauged a mark in the inside of the head, here are a few more pics:

123018287.jpg


and here

123018303.jpg


I also found that when at TDC the notch in the damper pulley doesnt point to 0 on the timing mark. Not sure if the damper is ready to fly off too.:unsure:
 

SKiddell

Well-Known Forum User
Yeah Gods and little fishes George -- somethings been flapping around in there.

Judging by the size of the gouge and the amount of aluminium swarf in there I would suspect that some would have dropped into the sump -- washed down by the oil flow, this will be sitting in the oil pan ready to be sucked up by the oil pick up or worse --- it already has.

I await the results of Albrechts diagnosis but a strip down might be on the cards.

The crank damper is explainable -- I have seen 2 "Euro dampers" one with the TDC slot at about 10 Oclock and one with the slot at about 2 Oclock. The timing pointer can be mounted either side of the block and caters for this. Plus there other belt configurations for AC and power steering etc that may add confusion. However dont rely on this info to explain it away competely -- further investigation is required to verify this.

Whereabouts are you George
 

Mr.G

Club Member
SKiddell said:
I await the results of Albrechts diagnosis but a strip down might be on the cards.
I sure hope not... :(. I will drain the oil and remove the sump and see if any nasties are left in there. Will keep you all updated - Cheers.

Located in North West London, near Wembley.
 

Albrecht

Well-Known Forum User
George,

Like Adrian and Steve, I am fairly sure that this is not good. The 'grinding' marks seem indicative of the timing chain whipping around ( I can't imagine anything else that would cause them ) but just how the chain would make marks in such a position I cannot imagine. The marks seem to be very close to the cam sprocket ( where the chain should not be physically capable of leaving such marks ) and on the 'tight' side of the chain too......... :confused:

As I think I mentioned before, I would replace the chain and all tensioner components as a matter of course. The costs incurred seem to me to be good insurance considering you are going to be taking off the sump and front cover anyway.

I have some unused stuff I can bring with me ( chain tensioner, both guides, new chain and a good cam sprocket ) just in case they are needed.

I think I also have both types of timing position pointers too - so we can match one up with your front pulley. But how come the pulley does not match up with the pointer on the front cover? Sounds like a mis-match to me - which raises suspicions ( and worries ) about the engine's history. Who has been messing around with it before it went into your car?.............

We were going to go to Japan today ( Weds ) but the 'wife' discovered that there was a bonus episode of Eastenders tonight and changed the booking to tomorrow ( Thurs. ). Either that or I made a mistake :rolleyes: ............. We have changed our return date too ( now going direct to Kyushu and then on to Sapporo ) so I'll be back in London on 9th January. Should be able to visit you during that week hopefully. Does that sound feasible to you?



Take your time over this George. Don't rush it and trust to faith. I think you need somebody to give you a second opinion and look over your shoulder. Hope you can wait until I return from Japan........

Cheers :)

Alan T.
 

Mr.G

Club Member
Alan,

Thank you so much for saying you will have a look over this. I feel somewhat better even with the prognosis looking so bad. Any time that is convenient for you is good for me.

As you say I will be patient over this and I will just remove the radiator and the timing cover so it will be ready for your inspection. Thanks again - it means a lot.

As for the parts, please do bring what you think I may need and I will reimburse you.

Thanks again Alan. :) Safe Journey to Japan.
 
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