Ford Scorpio Forum - Print Page


    
      
        Ford Scorpio Forum
        (https://www.fordscorpio.co.uk/cgi-bin/yabb/YaBB.pl)
      

        General >> Problems >> Valve timing - cam-chain position - help!
        
(Message started by: Mike_Floutier on Aug 13^th, 2008, 8:24am)

Title: Valve timing - cam-chain position - help!
Post by Mike_Floutier on Aug 13^th, 2008, 8:24am

Hi,

I just got my cylinder head back on (having got no. 1 piston to TDC and the cam-shaft sprockets correctly aligned AND having tried to keep the chain from dropping) but when I put the chain over the exhaust sprocket (keeping it taut with the crank, as the book says), MY paint marks on the chain were 2 links too high (ie. towards the inlet sprocket).

Question is,

1. have I pulled the chain too taut, and so got the wrong position, or

2. Did the chain slip over the crank sprocket (1 or 2 links)?

What should I do? I thought that, so long as the chain was taut, the timing would be ok, but the engine doesn't sound too happy; it will run but it stops by itself at idle. Mind you I forgot to re-connect the MAF (don't know if that makes any difference??

Anyway, what would you recommend doing? I need to be on the road by 11:30am - hehe!

Thanks

Mike

Title: Re: Valve timing - cam-chain position - help!
Post by Tompion on Aug 13^th, 2008, 9:01am

Make sure all the air hoses are on & not leaking.

If the relationship of the sprockets isn't as shown in the manual then it won't run properly - you'll see it gives angles (2.2 & 2.9) that a point on the sprockets should be when the pulley mark is TDC.

http://www.fordscorpio.co.uk/manual/engines/dohc2_3/2300CylHead.pdf

Dave

Title: Re: Valve timing - cam-chain position - help!
Post by bizzay1 on Aug 13^th, 2008, 9:08am

On the same link that Dave has given, if you scroll down to section 58, it explains how to check the timing using the marks and turning the engine.

Check the note there as well - if you need to alter the timing you need to fit another tensioner

Title: Re: Valve timing - cam-chain position - help!
Post by Mike_Floutier on Aug 13^th, 2008, 9:19am

Ok thanks, but I've already done all that I even went further, following the Haynes Granada guidelines by rotating the crank twice as well as once - ie belt and braces.

The point I'm getting at here is that EVEN with no. 1 at TDC AND cam-shaft sprockets at 2.2 & 2.9deg below horiz. IT IS POSSIBLE to locate the chain in different positions on the exhaust sprocket getting varying degrees of tautness ( possible by virtue of the tensioner - especially when it's compressed as it obviously is when new).

The question remains, apart from removing the lower, crankcase cover (would I need to drain the oil?) and checking the "gold" chain links, is there any way of knowing that the CHAIN (rather than the sprockets) is correctly located.

Does that make sense?

Mike

Title: Re: Valve timing - cam-chain position - help!
Post by Tompion on Aug 13^th, 2008, 9:43am

It's difficult to answer without seeing it, but if the sprockets and pulley are in the right place it should be OK. Doesn't it have the copper link for the exhaust sprocket?

Take up the slack in the way that the tensioner would.

Have you released the tensioner - wouldn't have thought there'd still be much slack.

Item 53 says:
NOTE: The timing chain must be taut on the
long side.

Title: Re: Valve timing - cam-chain position - help!
Post by Mike_Floutier on Aug 13^th, 2008, 10:23am

Thanks Dave, yes copper, I guess gold would be a bit extravagant - hehe. And yes, it is taut on the long side.

I understand the issue with the copper link lining up with the exhaust timing mark at 2.9 or whatever BUT that presupposes that the other special link is in the right place on the crank-shaft sprocket, which I can't see, that's why I was asking about the crankcase lower cover.

Anyway, I've just done a compression test on the cylinders and everyone's comments about getting the "black"valve re-seated and lapped are thoroughly well proved because, although all the other cylinders give 13-14 bar the "black" valve's cylinder has gone from 6 bar down to 4 bar, which explains my rougher running. This may indicate that my valve timing is ok because this is the level of roughness I would expect with one cylinder on virually no compression.

Hey-ho, Mrs F. is picking up a new thermostat and a pair of coolant temperature sensors from Allparts as we speak (have I told you that she's an angel!). So given the horrible state of the old stat and the fact that I've been able to successfully flush and reverse flush all elements of the cooling system this morning and have a nice newish radiator in place, I am confident that I'll be able to report that it's not over-heating and that the degree of rough running is managable.

I'll then run it for the next week or so like this until the new car is convered to LPG and then I'll get the head off again and get old "black valve" properley sorted prior to selling the car.

Many thanks again!

Mike

Title: Re: Valve timing - cam-chain position - help!
Post by Tompion on Aug 13^th, 2008, 10:36am

If the sprockets & pulley are in the right place, then the chain must be.

out of interest you say
"horrible state of the old stat"
What was it like?

You may find the compression improve a little - but I wouldn't hold your breath.

To be perfectly honest, especially given the mileage, It'll cost you more to put it right than you'll gain on the selling price.

Title: Re: Valve timing - cam-chain position - help!
Post by Mike_Floutier on Aug 13^th, 2008, 10:55am

I know that it appears that way from the instructions BUT believe me I've just fitted it and at first I put it on with MY chain marks lined up with the sprocket marks. I then noticed that I could ALSO fit it one link tighter and then two links tighter.

However, I think if I had used my chain marks instead of pulling the chain as tight as I could THEN when I rotated the crank (as suggested) the slack would have been taken out and the sprockets marks would then be out of position once the crank was returned to TDC.

Hence I really appreciated your insistance tht I rotate the crank fully because if I had used MY marks and not done this I would have had the timing out.

As it is I think it's ok - as you said!

Now to fit the coolant parts, fill it and test drive. I've had a bit of a reprieve so myfirst job is not until 13:45.

Will let you know how it goes.

Mike

Title: Re: Valve timing - cam-chain position - help!
Post by Tompion on Aug 13^th, 2008, 11:02am

Good luck :)

Title: Re: Valve timing - cam-chain position - help!
Post by Mike_Floutier on Aug 13^th, 2008, 10:35pm

Thanks Dave,

Well I drove my passenger to the Institute of Directors in Pall Mall and he didn't seem to notice that anything was amiss, I hung around a couple of hours and drove him back to the office, again no problems. Now I just got back from the airport picking up another passenger again no probs.

The new radiator is fine, the new thermostat now lets water through the radiator rather than jst blowing it up and the new coolant temp. sensor - well, I can tell you, this is the first time in 250,000 miles that that needle has not just been sitting on the bottom making the occasional twitch; for £8 I can't thing why I didn't do it sooner - hey-ho!

No. 4 cyl. is still at 4 bar so not much help there. When at idle, and mainly before it's warmed up I get this metallic tappping; like someone with steel fingernails drumming them on a tin can. Anyway, if I avoid idling I think I can make it last until the Lexus gets it's gas conversion. Then, if my wife can stand it, I'll get that head off again and sort that pesky valve out properly and sell it.

Thanks again for all your help guys, specially you Dave. I never dreamed I'd see the insides of my car's engine.

Mike

Title: Re: Valve timing - cam-chain position - help!
Post by Tompion on Aug 13^th, 2008, 10:44pm

Well done Mike,

Must admit I didn't think you'd get it done in time ;D

Dave