Cam / Timing belt and compression problem

jackso20 · Post by **jackso20** » October 25th, 2007, 8:06 am

Hi all, New guy here and this is my first post

This is actually a question on behalf of my mum, although I will be doing the work. I live in london so haven't seent the problem yet as she lives up north, but I will look over the weekend.

Problem:-
Cam belt snapped on the motorway and car needed to be towed to a workshop to be looked at. The mechanic has looked at the car and insists his information tells him its an interference engine and needs a rebuild.
I argued (over the phone) that it is not so he has tested the compression of the engine. Results are that it has no compression.
Thing is he says a rebuild is too much work for him so got her to get it towed home.

So....firstly, do you guys think he is speaking crap? Its a 1998 1.8 V6 from the UK. Non-interference right?

Secondly...any valid reason why there is no compression? Or do I have to have a rebuild.

Thirdly...If it does need a rebuild, its just a case of opening her up and changing heads right?

Would you go down the route of changing the cambelt and seeing what happens? Thats what I am thinking...

jackso20 · Post by **jackso20** » October 25th, 2007, 9:02 am

also, does anyone have a copy of the 'how to' cambelt change, with pictures? Maybe on a word doc or pdf?

hharb · Post by **hharb** » October 25th, 2007, 9:52 am

I'm not really sure if your mechanic is right or not but my advice is whatever you do, don't rebuild a k8 its a waste of money, u can get kldes for cheap, sometimes for free, or you could get a nice ze and have a good start.**** edit**** i just read its on behalf of your mum, so i guess you could scratch off that idea, unless your mom would like some more power...

jackso20 · Post by **jackso20** » October 25th, 2007, 10:07 am

Nah, she doesn't want more power......I wouldn't trust her with more power anyway!

So you reckon a cambelt change is the way to go?

Were there ever any intereference engins in mx-3's? I think the mechanic is wrong. Opinions?

1992blazeredgs · Post by **1992blazeredgs** » October 25th, 2007, 11:24 am

You can either check the online manual for a step by step procedure for changing the timing belt. Or check the v6faq, where tunes67 has good write up with pictures.

Also the k8 that came in the stock mx3 is a non interference motor.

Nate

andy · Post by **andy** » October 25th, 2007, 12:05 pm

Also if the timing belt is broken how did he check the compression?
I have replaced the timing belt 4 times, the first time took approx 12 hours.
the last time took 3-4 hours. By the way it wasn't the belt that went bad each time it was the water pump. If your in there replacing the timing belt you might want to consider replacing the water pump to.
The 1.8 v6 is a non-interference motor.

Andy P. 1.8T

wytbishop · Post by **wytbishop** » October 25th, 2007, 2:39 pm

I have seen non interference engines bend a valve when the cam belt goes. If the engine is old and the valve springs are tired the valves can float at high rpm making it possible for a valve to be opened farther than the lobe of the cam would normally do. A valve can be bent under normal dirivng conditions if the clearance is small enough. I don't know what the valve to piston clearance is in the K8, but I have seen this in the Nissan E16 engine more than once.

Also, it is impossible to check compression without a timing belt. If you're lucky 1 or 2 cylinders might be in the closed position, but on at least 4, and maybe all 6 cylinders, either the intake or exhaust valves are going to be open and not moving.