Ticking TDI

[manic]

Finally got my LR90 200tdi back on the road today.:):D:cool:
Its the first drive for 12 months so I cant remember whats normal anymore.

The steering was vague, wandering about - I just changed all track rod ends but then I do still have the drop arm to do.

There was no power to pull in second gear so I did one slow lap around the block before putting it back in the garage :(. But that's probably down to having set the pump to minimum fuel on boost and minimum fuel off boost, I have also reduced the throw of the accelerator and have new rear drum brakes with shoes that are too big..I hoped to let them rub till worn down! So not to worried about that at the moment as I still have some tuning to do there.

What I am worried about is a ticking noise, its pretty pronounced - changes with rpm - heard best when inside the car or at the passenger door.

It has just had a turners head put on it, new elring gasket, new bolts all torqued to manual and nothing found to be escaping around the head gasket when running. The timing and valve spacings have also been done, and it runs without the haze of smoke it used to have before the work.

The manifold gasket is new but harder to run your hand around! I doubt its leaking as I have it all on tight, but whats the best way to locate a manifold gasket leak so I can rule it out?

There was a tick before all this work was done - the blown head gasket - but this ticking sounds different, louder maybe.

What else could cause a tick?

[sheerluck]

Normally a tick like you describe is down to a leaky exhaust manifold. Does the tick get any louder or quieter as the engine warms up?

[redrovertdi]

Run the engine longer and look for soot around the manifold for the leak or you may feel it blowing whilst burning your hand at the same time:D

[manic]

Normally a tick like you describe is down to a leaky exhaust manifold. Does the tick get any louder or quieter as the engine warms up?

I ran it up to temperature a couple of times after adding new coolant and the tick remains pretty constant.

I suppose as well as the manifold I better check all the connections on the exhaust, including turbo housing, dump pipe , mid section.

I hope it is just a bit of exhaust noise!

[landiematt]

Not a lash cap?

[Davie]

Hi there, I have found listening through a short length of hose or similar an aid in finding just where a particular noise is coming from. Just hold one end to your ear and move the other end around the suspect area, it gives a good indication.

[manic]

Not a lash cap?

I renewed all the valve stem caps if that's what you mean. I will check/set the clearance again to be sure.

[manic]

Hi there, I have found listening through a short length of hose or similar an aid in finding just where a particular noise is coming from. Just hold one end to your ear and move the other end around the suspect area, it gives a good indication.

Gave this ago around the manifold end of the engine but couldn't pick anything up. :(

I will do the valve clearance again and I still have to change oil and filter - then will take a couple more runs and see what I can find. If its still ticking I will assume its a manifold leak that needs tracing.. I may take it to MTQ for a check over also to be sure.

[manic]

Well I think I may have found the problem. I checked the length of the exhaust and found a clamp that was loose enough to spin.

I then checked the valve clearances and #6 was WAY OFF! I don't know how I only set them a few weeks back, perhaps something shifted or I switched off for a moment when I was setting them (more likely)... it was so loose that the cap had come off the valve stem but fortunately I was able to rescue it and there was no damage. All valves good now.

I'm unable to check if the ticking has gone because I found coolant weeping from between the thermostat housing and outlet/cover. Turns out one of the threads in the housing has pretty much stripped and it doesn't hold enough torque! I've dumped half the coolant and removed the housing for helecoil - it'll all go on with gaskets AND RTV this time to be sure.

Thanks for the pointers.