If you're reading this you may have the same problem I have, the ticking disco. My has gotten progressively worse over the past month. I brought to my Rover mechanic who suggested that itcould be a cracked/damage flex plate. He wasn't 100% sure if the 4.0 engines have a flex plate, but he said if they do he would put his money on that. Thoughts?

Then he said if its not the flex plate could be a cam bearing??

My tick is rooted in the center of the engine (I think between the engine and trans) and is clearly heard from underneath the truck. I soon as I raise the rpm's over 1,200 the tick stops. Centrifical Force perhaps, is taking over and silencing the tick?
Also, when I shift from P to R the tick changes note. Same when I shift from R to N and N to D. I think its coming from between the engine and trans. Thought?

 

Well, I will take another trail and suggest that this tick is being masked by oil pressure increasing, instead of centrifugal forces. There are a number of posts and I believe a technical section write up on ATF flush.

 

If you can tell the tick is coming from inside the engine and not related to SAI valve or an exhaust leak and goes away with increased throttle/ Increased oil pressure you possibley have a lifter that is collapsing due to wear or funk in the lifter itself or possible low oil pressure driving the entire senerio. I was thinking about this the other day since I too get a tick from time to time on my 03'. I'm willing to bet that a tick sometime is a direct indicator of overhaul oil system clearances driving oil pressure. As you bearing clearances and pump clearance wear you pump output because less most noticable at idle rpm. With the low oil pressure a weak lifter has a difficult time staying pumped up creating the tick. How long will she last is the Big question. I've already rebuilt one engine and if I need to do a second I'll do so as I love these trucks.

 

If it's about time for an oil change, how about adding some Marvel Mystery Oil in there, to see if it changes? MMO is very thin oil, on the order of 7 weight. If it doesn't make much of a change in a few days, you'll be removing it when you change oil. The ATF flush of the oil system is said to help the "tick" which could be from removing gunk on lifters. There is a product called Auto-RX, which is a slow working solvent. It solvents off the sludge slowly, keeps it in suspension, oil filter takes it out. Your oil turns black using this stuff, and you have to change filters every 1000 miles to trap the gunk. About $21 for a bottle. While some might call it snake oil, I have seen it work (something made my oil very black). Now does it get it all, don't know. Does it work as fast as the ATF flush - no. The Auto-RX product supposedly came from the printing press industry, where it was used to clean large hydraulic systems during operation.

 

It's the liners moving. Probably only does it when warmed up and only at idle.

 

Please do NOT fill your engine full of transmission fluid and run it to "flush" the engine.
Either use a off the shelf engine flush or use the Marvel Mystery Oil.
Check your catalytic converters, when the guts inside them fall aprt they can make this tick that sounds like it is coming from the bottom of the engine.

 

Here's a copy of a recent post on the subject:

03 Tick Solution... ATF Flush and Blow out the Pipes...
Disco mike recommended last weekend that I try flushing my engine with ATF fluid for the tick that has been so widely debated and drives me up the wall at stoplights (I had called for a pep talk and pointers on my plugs and wire job).

I swapped out my W5-40 syn, put in 6 quarts cheap ATF, ran it for 30 minutes, and replaced it with 15w-40 Rotella and a quart of Magic Mystery Oil, started it up and, no tick! For 15 minutes, and then started up again, although slightly quieter.

Yesterday, I took the truck on its first ever 300 mile road trip. Since I have owned the truck, I have pretty much driven it like a senior citizen, and rarely gone over 60. Yesterday, I had a time constraint, a can of BG44k in the gas tank, new plugs and wires, and said to hell with it and was pushing 75 pretty much the whole time. Pulled off about 150 miles into the trip to walk the dog, and, NO TICK. pulled off a few more times, tick is gone, drove about 60 miles around today, no tick. I am pretty sure the actual issue was a stuck lifter, and I am thinking that the flush combined with pushing the truck to the point that it could unstick itself may be what did the trick. Don't want to jinx myself, but I figure it is my obligation to tell someone if I have found a simple possible fix for this PITA problem.
__________________
Disco Benjamin
2003 Discovery II S 75k, Rebuilt Front Driveshaft, ReMan PS Pump, New Hoses, Front Cross Bar Thule and High Tower Thule on Back, Peak Global Coolant, Chalkboard Headliner, STI Plug Wires, Platinum +4 Plugs, Akebono Pads, 03 Brush Guard

On Deck: Goodyear Wrangler HP All Weathers, OME 2", Steel Brake Lines.

1996 BMW 328i 210k

 

Is your mechanic from England? I read on Ashcroft Transmissions website that there is a problem with the diesel engines that have automatic transmissions cracking their flex plates. We do have flex plates, but I don't know how often they crack.

EDIT:

http://www.ashcroft-transmissions.co...d&productId=52

I guess it's not exactly a flex plate, but part of the converter that cracks.

 

You guys can do whatever you want, my truck has over 205k on it and it has never had a engine flush of any kind.
But then again, I change my oil every 5,000 miles and use a good oil and filter.

Read up.
ATF as an engine flush - Bob Is The Oil Guy

 

Spike, have you owned it since new or very young? For those with high miles older vehicles, with previous poor maintenance practices for the neglectful previous owner, what are good ways to get back to where the engine should be?