dil Posted May 25, 2002 Share Posted May 25, 2002 Hi all (especially those of cam belt knowledge) my cars about 6 years old,done 36000 miles, I know the recommended cam belt change interval is 60000 miles or 5 years but do i really need to change it, with only half that many miles. I'd rather spend the money and buy an exhuast, which i've been uuuuummming and ahhhhing over for 5 months. I've heard that if you look at the cambelt and you can see the manufactures name or letters on it, it needs changing & quick. Is this true? b'cos i can see toyota on mine!!!!! cheers Quote Link to comment Share on other sites More sharing options...
Alex Posted May 25, 2002 Share Posted May 25, 2002 Its a very important part of your car...is it worth risking the engine for a £40 belt? Me thinks not.... Should cost £200 max to get it fitted. Including extortionate labour!! Quote Link to comment Share on other sites More sharing options...
Digsy Posted May 25, 2002 Share Posted May 25, 2002 Visual inspections of any kind are very hit and miss with timing belts. They can get cracked to h*ll and still run fine, or look like they just came off the shelf and suddenly let go. If you are at all worried then I would get it changed (I did - at 27000 miles). At least you know you are starting with a "clean sheet". Might be worth pricing up how much extra it would be for a front crank seal replacement at the same time. I've got a very slight weep on mine and I wish I had had it changed while they had the front end apart to change the timing belt. Oh, and given Rob's experience, make sure you take it somewhere that doesn't have to use a blowtorch to get the crank pulley off! Quote Link to comment Share on other sites More sharing options...
dil Posted May 25, 2002 Author Share Posted May 25, 2002 Well I guess that told me, cam belt change it is then, whats this front crank seal, I dont want to tell the mechanic to have a look at it, b'cos 9/10 they'll tell you something needs changing even if it doesnt. How can i see this "weep" and more importanatly were am i supposed to be looking? Cheers Quote Link to comment Share on other sites More sharing options...
Digsy Posted May 25, 2002 Share Posted May 25, 2002 Its right at the front of the "metal part" of the engine, sandwiched between the back of the crank pulley / timing sprocket and the oil pump at the front of the cylinder block. You won't be able to see it directly because of all the bits in the way, but if there is any wet oil around there then chances are its coming from the front crank seal. You will have to take the undertray off to see anything at all. I'm not implying that there will be anything wrong with it. Mine is leaking a tiny bit but I don't leave puddles of oil around or anything. In fact I don't even notice and loss of oil at all (for how often I check it). I just happen to have had my timing belt changed first. If it had happened the other way around I would have definitely got them to change the front seal at the same time because the amount of "pulling about" is virtually the same for both jobs. Quote Link to comment Share on other sites More sharing options...
dil Posted May 25, 2002 Author Share Posted May 25, 2002 I'll get underneath the car tomorrow and have a good look around, theres also a sharp metallic noise when i 1st start up in the morning that seems to be coming from somewhere underneath the car, that i need to check out, and i think the steering pumps playing upto, dont know if they are related? cheers Quote Link to comment Share on other sites More sharing options...
Digsy Posted May 25, 2002 Share Posted May 25, 2002 If its a "langa-langa-langa" kind of noise that goes away after a couple of seconds after you first key on then it could be a touch of piston slap - a tad annoying but nothing to worry about unless it gets really bad or prolonged. There was an espisode some months back when a few people were reporting strange noises from their PAS pumps, but to my knowledge no-one ever go to the bottom of what it might have been. I have noticed that mine makes a slight while from cold, but it dissappears after a while - at least it isn't whining any more when I get to work (25 miles away from my house). Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 25, 2002 Share Posted May 25, 2002 What is piston slap? I've heard it mentioned before, but how does it manifest? What's going on in the engine when you are experiencing it? -Ian Quote Link to comment Share on other sites More sharing options...
Bradb Posted May 26, 2002 Share Posted May 26, 2002 Tut, Ian even I know what a piston slap is... geez. Quote Link to comment Share on other sites More sharing options...
Digsy Posted May 26, 2002 Share Posted May 26, 2002 Its the thing that goes "langa-langa-langa". Its something to do with the side loads on the piston reversing at top-dead-centre & bottom-dead-centre. Piston pins are usually offset by about 1mm towards one side of the cyinder bore (the "thrust side" on the power stroke) to help rememdy this. (Getting to the limits of my knowledge here. I need to talk to a Development Engineer at work for a full description. They have much bigger brains than us ignorant Designers! ) I'll post more info on Monday if I remember. Quote Link to comment Share on other sites More sharing options...
Myles Posted May 26, 2002 Share Posted May 26, 2002 Originally posted by Ian C What is piston slap? I've heard it mentioned before, but how does it manifest? What's going on in the engine when you are experiencing it? -Ian Forged pistons tend to expand slightly as they heat up & fit the cylinder (which normally has only one spark plug - but may have two).... therefore , when cold they `slap about' a bit (as explained by Darren)`til the engine approaches operating temp ..... another good reason to only drive on part throttle for the 1st 10mins or so from cold . Forged pistons are good Quote Link to comment Share on other sites More sharing options...
Adam W Posted May 26, 2002 Share Posted May 26, 2002 Does the MkIV have forged pistons as standard? I looked into some for my Mk3 . . . £££££££ Quote Link to comment Share on other sites More sharing options...
Myles Posted May 26, 2002 Share Posted May 26, 2002 I dunno! .... you just read the full extent of my technical/mechanical expertise Quote Link to comment Share on other sites More sharing options...
Myles Posted May 26, 2002 Share Posted May 26, 2002 as the earlier 4agze engine had them ... complete with ceramic coated tops .There , I've left myself wide open ...please feel free to contradict me as I never actually took the pistons out of the 4agze to check (blind faith ....follow where I lead) Quote Link to comment Share on other sites More sharing options...
Digsy Posted May 26, 2002 Share Posted May 26, 2002 MKIV.com doesn't specifically mention the pistons being forged, but it doesn't say they are cast either, so your guess is as good as mine at the moment! Since this thread has moved off in its own direction, I've started a new one in Techincal where we can discuss slap to our heart's content... Quote Link to comment Share on other sites More sharing options...
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