Same old story - start up rattle

[kernowman]

HI, sorry to bring this one up yet again, but I am a bit confused over one point. I am lucky enough to have a vehicle on which a previous owner had the timing chains, guides etc. replaced with the newer versions. This was done about three years ago (25,000 miles back). However, I now have a brief, but quite noisy rattle for fractions of a second on start up. There are no other symptoms while running, nor does the rattle last for more than a very brief period. At the time the work was done, a restrictor pencil type thingy was not put in the oilway, so I have just done this myself. Results are dissapointing - sometimes I can leave the vehicle for five or six hours and I get a perfectly quiet start - other times it will rattle if left for only half an hour or so. In all cases if I leave it overnight I get a morning rattle. After all that, I will get to my point of posting - I see that there is a later front timing chain tensioner (a cylindrical bit sticks up above the hexagonal head, whereas mine is flush). Would this make any difference if I fitted one of these? In theory, I can't see why I get a rattle now, as the restrictor 'pencil' should in fact hold oil in the passageway - is there any other way oil can drain back when the engine is switched off?
Out of interest, I replaced the upper and lower manifold gaskets when putting the restrictor in - highly recommended - it made a very great difference in performance and idling. Must admit, the original gaskets were in a bad state, though.
Richard

 

[Howard]

The revised tensioner may well help. The other thing that may help is to change the engine oil to synthetic like Mobil 1.

 

[kernowman]

Thanks Howard, using semi-synthetic at the moment and only just had an oil change, so might hold off that one until I have tried everything else. Will try a new tensioner if I can find out where I can get one. In fact, in desperation I will try anything (apart from selling the Explorer).
Richard

 

[BIGHVM]

Also try an engine flush (Wynns or similar), as the lifters can get slow after grime gets in them- that should fix you with the Mobil 1 or any decent full synth. I would recomend changing that tensioner you mentioned, that is the old one, in the oom12 kit that I used that comes was a part of it, I believe you can get it on its own from ford, I had the same problem as you for a few seconds-changing that fixed it for me. I think the spring in the tensioner gets weak after a while.
One thing to watch out for is the rubbish washer that comes with that part its so thin it bends if you blow on it and distorts if a spanner touches it!........I used the old copper washer from my old part, just flatted it on a piece of wet and dry on glass before using it again- all fine no oil leaks and silence at last!

 

[CDW6212R]

... the spring in the tensioner gets weak after a while....

The cam chain tensioners on each head have a spring inside. Those will become weak after long use. They cost about $25 each here and they are the easiest things to change. I suggest to anyone with a SOHC to replace those regularly, say every 50-75k miles.

The rear one can be done in about five minutes, after you remove the right inner fender liner. It takes a very long extension, socket and ratchet. The rear one is flat on top. Regards,

 

[kernowman]

Thanks to everybody. I have got a front tensioner on order and will post with the results when I fit it. Interested to hear about the rear tensioner, particularly how easy it is to fit. Nobody seems to mention the rear one very much - wonder if folks assume it cannot be replaced without pulling the engine, as you need to do when replacing guides and chain.

 

[CDW6212R]

That's why I posted the picture. With the plastic inner fender pulled away, you can see straight in to the tensioner. I sat at the front wheel and from afar it looked like I was tightening a lug nut. Those take 42lbs.ft. of torque, those frail washers that come with them will crush nicely. When you get the old tensioner out, compare the resistance of the two. Crush the plunger of each with your fingers. Both of mine were weaker than the new parts, even my front one which had been changed before. Regards,

 

[kernowman]

Don, it was great to have the picture - makes the whole situation so much clearer. Will post my results when all is done. Thanks again.
Richard

 

[CDW6212R]

Yes, and the head of that is very thin, you really do need the extensions to get the ratchet to where you can get both hands on it.

 

[Velocity4x4]

very helpfull pic looks like ill be off to fords on tuesday ....thanks.....

 

[BIGHVM]

Hmm I will find the part number in the uk for the reqr tensioner- guess it would not hurt to replace it.

 

[kernowman]

My Ford spares dept. looked it up for me - called a rear tensioner bolt (strange) - price is around 24 quid plus washer at 2 quid. Was going to have a look in the US to see if I could get a better price, but have not got round to it yet. Wondered if the dreaded startup rattle can also come from the rear chain as well - we all seem to concentrate on the front chains. Will definitely do my rear sometime, now I have done the front with the new version tensioner and put the restrictor in the oilway.

 

[Explorerman2]

Try STP

I read on the American Forum that STP can reduce start up rattle. I don't have any rattle but I put a can in when I refilled with Mobil 1 (probably a contradiction in itself) I'm not a great believer in additives and do not necessarily recommend this even though I am trying it! For those who do not know STP it has the consistency cold of golden syrup and it's very sticky. I guess the theory could hold true that when cold it does not drain away and therefore there's oil residue where it needs to be at start up. To be my own worst theory critic, anything that is sticky enough to hold in place, may well restrict oilways anyway. On the other hand if it's like the restrictor "pencil" but a chemical solution, that's not a bad thing. However at Halfords it's cheap enough, so it's painless to try it, it's just added to the oil- I did it in Halford's car park, it's been around for ever, so can't do any great harm and even if it's snake oil, I haven't taken a big gamble.

 

[CDW6212R]

STP was very good long ago when oil quality was not what it is now. The viscosity is not that thick after it is in and run for a bit. It's a good additive for an engine that needs oil but you want to get another few days before changing oil. It helps old oil, but it doesn't improve new oil. I prefer Amsoil for its extreme changing intervals(25k). Take care,

 

[BIGHVM]

25k oil change- not in my life, minimum once a year with the frail timing chain set up on the Ex!
I dont trust the engine that much after all the horrer I have heard about total distruction when the chain snaps!

 

[kernowman]

In another thread 'Frustrating Day', Howard recommends Mobil 1 synthetic which I have heard getting good mention before. However, somebody else put to me about using Castrol Magnatec 5W-30 A1, as they reckon it gives better startup protection - any comments or has anybody tried this oil, which I believe is a semi-synthetic? Castrol website raves over it - is it just selling hype?

 

[CDW6212R]

STP was very good long ago when oil quality was not what it is now. The viscosity is not that thick after it is in and run for a bit. It's a good additive for an engine that needs oil but you want to get another few days before changing oil. It helps old oil, but it doesn't improve new oil. I prefer Amsoil for its extreme changing intervals(25k). Take care,

My Amsoil change of their filter and oil was about $55. I went to 11,000 the first time, but needed some temporary oil for my V8 that is going to be swapped this month. I plan to go 12,500 miles, the recommendation for severe duty use. Al here has gone over 25k more than once, and he has the same SOHC as we do.

The best oil is better than going cheap and changing it every 3,000 miles. Regards,

 

[kernowman]

Decided against Castrol Magnatec as it appears to not be synthetic, only having, as Castrol say, 'synthetic properties'. Mobil 1 definitely seems the best. Have saved up my hard earned pennies and bought the oil, just waiting for the filter to arrive. Will post the results when I have done the change (and flush).
Mobil 1 is expensive, particularly for us Cornish piskies (pixies) down here. Lucky enough to be able to afford it as I have a good job mining pasties in our local Cornish Pasty mine. Feel sorry, though, for some of the lads who have to work in the treacle mines.

 

[kernowman]

Carefully flushed engine with Wynns, and put in Mobil 1 and new filter. Guess what - rattles on start-up now nearly every time from cold, which is worse than before. Rattle is still only for a split second, and at least there are no rattles when running. One consolation is that I know I have got the best protection I can get for the engine with Mobil 1. Trouble is, where do I go now? First of all did the restrictor - made no difference, then the new type front tensioner, again made no difference. Now have done the oil and it appears to sound worse. I am now

 

[Howard]

Are you sure that the rattle is the front timing chain? Could it be the rear one? Maybe the rear tensioner is worn. Is the rattle the chains at all? Some careful diagnosis is required to pin down where this noise is coming from.