Thread: Ticking sound when in drive

You may have damaged a lifter, when over heated , or ,depending on how hot it got it could have accelerated engine wear, so now , at operating temperature the oil pressure is lower, especially in drive when engine revs are lowest, putting into park will lift revs enough to raise oil pressure enough to quieten the lifter, m and s lights could be xyz switch , low battery or trans / torque converter fault , power will feel low when this fault is current as trans will be stuck in 3rd or 4th gear

Have you checked the exhaust manifold bolts for tightness?

Thanks for the suggestions.

I don't think it is likely to be due to oil pressure, when in drive it taps through all rev ranges, and when in park no tap can be heard through rev ranges. I did look for exhaust manifold leaks and couldn't see anything obvious, but stopped looking after noticing it happens when selecting drive. I've got a stethoscope so may go hunting today.

I'll also play more today with gear change while driving to see what I can determine.

It's interesting what you say about the torque converter, I'm used to driving a manual, and have always felt my Disco is in the wrong gear. I prefer sports mode, even though I don't drive aggressively.

Cheers ... Fizz

Ticking under load (I assume ticking speed increases with revs?), maybe a loose liner tapping on the underneath of the head . Not an unusual result (so I'm told) for an engine of this type if badly overheated. Perhaps you could try disconnecting the HT leads one at a time with engine going and in drive to see if noise goes away and isolate to one cylinder/bank ?, similar to when isolating a cracked piston.

Deano

Originally Posted by discorevy

You may have damaged a lifter, when over heated , or ,depending on how hot it got it could have accelerated engine wear, so now , at operating temperature the oil pressure is lower, especially in drive when engine revs are lowest, putting into park will lift revs enough to raise oil pressure enough to quieten the lifter.

Perhaps you weren't far wrong after all.

I spent some time trying to isolate the ticking, taking into consideration the advice here. Using a stethoscope I was unable to auscultate any undue mechanical noises. I really convinced myself it sounded more like an air/exhaust/compression leak.

I noticed discorevy was right that the sound did get louder when the revs dropped, but also louder when driven. From inside at tickover in park I couldn't hear the noise, but it was still there under the bonnet.

Convinced that she would be fine despite the noise I went for a hard test drive. She definitely felt poorly powered, and a slight roughness in low revs.

On returning I noticed there was a lot of coolant consumption, hoping this was just air released after the initial coolant pipe overall I purchased a normal (turn over) compression tester. The let down pressure tester I used previously showed no pressure leaks. Using the new one, cylinders 3 and 5 developed 50 psi (2 cranks) 75 (5 cranks) all others had 100 + 150. So much for the let down technique.

The coolant consumption tells me the head gasket is gone, though no water has been seen at the exhaust.

Next step - figuring out how to get the head off. Does anyone know where I can find an electronic version of a maintenance manual?

Thanks ... Fizz

It does sound like you may have a cracked block and/or a loose cylinder liner. The typical noise of a loose liner is a kind of double "click-clack" with every cylinder pulse and gets worse as the engine heats up. it is usually loudest at low revs. Typically a major overheat will do this to one of those engines. If that is the case another second hand engine may be the cheapest option.

Originally Posted by bee utey

Have you checked the exhaust manifold bolts for tightness?

Ill second this. I had exactly the same issues and noise on my 2000 V8 auto. After all and sundry told me the usual "your head gaskets gone", I got under the car, nipped up the down pipe manifold bolts and hey presto, ticking noise eliminated. Put some spring washers under the nuts too, keeps them from coming loose again.

Just saying....

This is a video of the noise. What do you think?