Harsh / rough engine above 2500 rpm in all gears - is it normal?

Hi all, my Disco 2, 2004 TD5 runs really well except for the roughness / harsh / noisy engine at about 2500 rpm and above. In top gear below 50 mph all is quiet and smooth but as speed is increased the engine gets quite harsh / thrashy and at 70 mph sounds like something is slightly out of balance - almost a "pulsing vibration" type of noise. Not checked all the transmission oil levels yet but it has no obvious leaks and the manual gearbox is smooth.

The engine is new, as is the clutch and flywheel. The engine was replaced due to a blown head gasket so I guess loads of water (steam ) went through the cat? (I assume it has a cat?) Would a faulty cat produce these symptoms?

Car drives well other than this.

Any comments welcome - it is driving me slowly insane!

John

First thing to check would be engine/gearbox mounts. did they use the old engine mounts when the engine was replaced?

You can check them by getting under the front of the disco. Looking at the mounts from the bottom there is a small hole (about 10mm dia) in each mount. stick a pencil through it until it touches the rubber part of the mount. should be +10mm between the rubber and the metal housing. if the rubbers at the bottom then the mount is knackered (normally drivers side that goes first)

Yes the old engine mounts were re-used.. I will check them asap.. do you know how to change them - is it tricky?

I have changed all the oils now and the transmission all sounds sweet - I am pretty sure the harshness is from the engine. A few people seem to think it is normal but I cant believe they would have sold many if they are this noisy at motorway speeds...

I will just keep replacing bits until I find the problem. Not sure how long my enthusiasm for this car will last!

John

Mines the same! Been trying to get to the bottom of it for a couple of years till someone on Australian forum suggested mounts. My drivers side is stuffed. Got the mount off eBay but not got round to changing it yet. Doesn't look a nice job!!

hmmm... I had a good long run yesterday up the M6 and after very careful listening I am pretty sure the engine is causing the noise.. it sounds very much like an out of balance front prop shaft but it pretty much goes away when the throttle is backed off. Its hard to tell really. I have a feeling you are right about the engine mounts. I have had a look and they are a bit tricky to get at!! I will see if anyone has done the job and can offer any advice. Do you have a link to the seller of the engine mounts?

John

I was lucky and paid 99p for mine (came from DLS). there is a how to on the AULO forum. Got it saved as fav on pc at home so will post link later

Have you considered the wastegate modulator as what you describe sounds similar to what this chap had:

www.discovery2.co.uk / Waste Gate Modulator - Over boosting

duff wastegate gives a kangaroo effect like a very bad misfire

could be rear prop donut?

Hi all - been away sailing for a week - the engine mounts have arrived so I will fit them this weekend and let you know if it solves the problem.. they both seem to be goosed - the rubber is down at the bottom of the mount housing. I believe there should be a 10mm gap - mine are touching!

John

Update....

The new engine mountings are now fitted and made a big difference! (thank God!). It cruises at 80 mph now with just wind noise and a bit of a drone from the engine so I guess its as good as it is going to be. The old mountings were goosed - the rubber bits were resting on the metal holder - the new ones gave a clearance of about 10mm. I have also fitted a de-cat pipe which has improved the response from the engine quite a lot... certainly worth doing!

The engine mountings were not too bad to do - I managed to get at the drivers side by removing the fuel cooler and although it was a bit tight everything came undone relatively easily. The passenger side was easier - I did not remove the turbo - a "universal joint" adapter on the socket allowed access.

The de-cat pipe was a nightmare! The crossmember really has to come off and despite buying a good quality 6 sided socket two of the bolts rounded off and I had to grind them away to remove it.... (I used a dremmel - very useful little tool for tight places!) The pipe is just a bit awkward to get in and out but was re-fitted with a bit of fiddling. I found it easier to attach the pipe to the exhaust first and then to the manifold.

Overall the jobs were well worth doing and in particular the new engine mountings have made a huge difference to the car - its much more refined at motorway speeds.. 80 mph used to be unbearable but is now relaxed and quiet.

Hope this info helps... and thanks to all who took the time to offer advice... new gearbox mountings tomorrow - and replace the bit of plastic under the engine..

.... so to get from a clattery, noisy rough car to a relatively quiet refined one I have had to fit recon injectors, new engine mounts, bin the EGR valve and fit a de- cat downpipe... well over a £1000 but I paid under the odds for it so I am still on the right side of its value.... hope it keeps going for a bit now - I am sick of crawling under it!

John

Here is the info from the Ozzy Land Rover forum....


To see if your engine mounts have collapsed crawl underneath and there should be a 10mm+ gap inside the bottom of the mount to the base of the rubber (small round hole). In this case the rubber was pressing out the hole. (same with me!)

RAVE suggests having to remove the turbo, the centrifuge oil drain pipe and the 2 mounts that bolt directly onto the engine block. This is an alternative that worked for us. (I did not remove any of these)

Tools needed
10mm socket and or spanner for the fuel cooler (bottom 2 are hard to get at!)
18mm socket
15mm socket
2 ratchets
Jack with plenty of lift and/or blocks of wood
Ratchet extensions 40cm+ would be best (suggest 1/2")
Universal socket knuckle
Screw driver to remove radiator top cowl (not needed)
A mate to lend a hand and crawl under the vehicle. Long arms

and not all thumbs preferred. (I did it single handed but a helper would have made the job much easier)

Degrease both sides and underneath if needed. Whoever is under there will appreciate it.

First time doing this for both of us and job took 3.5 hours.... next time should be able to get it down to 2.5hrs with these instructions (took me 4 hours)

If a dual battery is installed adjacent to turbo it may make getting the LH engine mount tricky or impossible as the mount exits through that area. SUGGESTION: before going further see if you can pass the new one down through that section.

1) Disconnect battery - advisable at best of times

2) Remove engine cover (underneath)

3) Remove radiator top cowl (I didn't)

4) Remove the 4 bolts retaining the fuel cooler 2 short on top and 2 longer below. (tricky to get at the bottom bolts)

5) Loosen on both engine mounts the 2 bolts to the chassis and the one to the mounting bracket off the block (at least this way you know that you can get both sides done)

6) Remove all 6 nuts and invert the bolts back through the mounts downwards (safety precaution and allows sufficient engine movement)

7) With jack placed as safely biased RH of sump lift motor. In our case the acoustic cover on the back on the motor had to come all the way up to touch the firewall. This lifted and rotated the engine enough to remove the RH engine mount and replace with new one.
NOTE1: the new one was about 15mm higher that the old collapsed one. Engine mount removed and replaced from below.
NOTE2: Double check the matching up of the locator pin on top of the engine mount to the bracket.

8) Replace with the new engine mount and place the 2 bolts back down to locate properly.

9) When lowering jack - Slowly - ensure that the top thread positions through bracket.

10) Now that the RH is done time to move to the LH which has a heat shield over it that needs to be transferred to the new mount.

11) With jack placed as safely biased LH of sump lift motor. In our case the acoustic cover on the back on the motor had to come all the way up to touch the firewall that lifted rotated the engine enough to remove the LH engine mount and replace with new one.
NOTE1: the new one was about 15mm high that the old collapsed one. Engine mount removed and replaced from ABOVE.
NOTE2: Double check the matching up of the locator pin on top of the engine mount to the bracket.

12) replace with the new engine mount and place the 2 bolts back down to locate properly.

13) When lowering jack - Slowly - ensure that the top thread positions through bracket and that the heat shield is sitting properly.

14) Move the mounting bolts the right way around and tighten properly

15) Tighten the top nut.

16) Repeat for the other side.

17) Replace fuel cooler.

18) Replace radiator cowl and radiator cowl and reconnect the battery.

19) Double check that you haven't dislodged wires or anything whilst working through the gaps especially on the turbo side.


Start motor and enjoy the serenity..... (agreed!)

good to know your sorted. must get my a$se in gear and do mine!!

Final word.....

I have just replaced the gearbox mountings and it had made a big difference again... so much smoother and it cruises at 80 plus with no intrusive noise... absolute bliss! I guess it makes sense that if the engine mounts were goosed then the gearbox ones were too...

Easy job to do - driver's side just 2 15mm nuts to remove - jack up the gearbox a bit and it slips out. Passenger side needs the bracket removing but it was easy to do (for a change!) and fell out when the box was lifted..

Well worth doing - its amazing how much difference 4 new bits of rubber have made!

John

johndenney said:

Final word.....

I have just replaced the gearbox mountings and it had made a big difference again... so much smoother and it cruises at 80 plus with no intrusive noise... absolute bliss! I guess it makes sense that if the engine mounts were goosed then the gearbox ones were too...

Easy job to do - driver's side just 2 15mm nuts to remove - jack up the gearbox a bit and it slips out. Passenger side needs the bracket removing but it was easy to do (for a change!) and fell out when the box was lifted..

Well worth doing - its amazing how much difference 4 new bits of rubber have made!

John

Click to expand...

Hi John, this sounds like really worthwhile work, so could you please give me more info about parts ie part no's, costs, where to buy from etc.

And thanks for posting your report - we'll make them into a properly built car in the end !!!!

Cheers
Dave

Hi Dave, Got the bits from Rimmers i think - I will fish the boxes out of the bin and post the details tomorrow.... when I rang they new exactly what I wanted..no problem... I bought genuine LR parts by the way!

ps - its running so much better now.. its like a different car. I am a bit of a pain when it comes to cars - hate noises and clatters and bangs and I have to say today is the first time I have driven it and been happy!

Will check out the details of the parts tomorrow...

found the link...
Land Rover Discovery 2 Engine & Gearbox Mountings at www.rimmerbros.co.uk
I think the engine mounts were £40 ish and the gearbox were £30 ish.. dont get the aftermarket ones...

John

johndenney said:

Hi Dave, Got the bits from Rimmers i think - I will fish the boxes out of the bin and post the details tomorrow.... when I rang they new exactly what I wanted..no problem... I bought genuine LR parts by the way!

ps - its running so much better now.. its like a different car. I am a bit of a pain when it comes to cars - hate noises and clatters and bangs and I have to say today is the first time I have driven it and been happy!

Will check out the details of the parts tomorrow...

found the link...
Land Rover Discovery 2 Engine & Gearbox Mountings at www.rimmerbros.co.uk
I think the engine mounts were £40 ish and the gearbox were £30 ish.. dont get the aftermarket ones...

John

Click to expand...

Thanks for that John, that's brill. Sounds like you are in danger of actually starting to like your Disco now?

johndenney said:

Final word.....

I have just replaced the gearbox mountings and it had made a big difference again... so much smoother and it cruises at 80 plus with no intrusive noise... absolute bliss! I guess it makes sense that if the engine mounts were goosed then the gearbox ones were too...

Easy job to do - driver's side just 2 15mm nuts to remove - jack up the gearbox a bit and it slips out. Passenger side needs the bracket removing but it was easy to do (for a change!) and fell out when the box was lifted..

Well worth doing - its amazing how much difference 4 new bits of rubber have made!

John

Click to expand...

Just as a matter of interest, John, how many miles has your 2004 done? My 2002 has done 172,000kms so about 108,000mls.

Cheers
Dave

Hi, Its had a hard life i think - 118,000 miles now.... when I bought it last month it was good to look at but "dog rough" to drive - despite its brand new engine.... The bits and pieces I have done seem to have sorted it out now, so I am quite pleased with it.

I have bought some Waxoyl to tidy up underneath and I will sort out a couple of very minor blemishes on the bodywork when it warms up a bit. I am expecting more troubles soon () but most things seem fixable so I am not going to get paranoid about it. I have a bit more time on my hands now so I can fix things myself.

Oh and yes.... I am beginning to see the appeal of Disco,s... but still maintain that its not a car for the faint hearted!

ps - must look out for a late model, low mileage write off... I am sure I will need a shed load of spares when the transmission etc.. gives up the ghost.

Re-mapping is now complete - a nice guy from Dynachip (Mike) - he races Defenders and is very knowledgeable ref all things Landrover. The car is truly transformed. It pulls like a train and it is well worth £225! He was good enough to check all the diagnostics - he had the Landrover main dealer software (Test book?) and was very thorough... I am glad i did not spend twice the amount at TD5 Alive..... I think their prices reflect all the advertising they do!

I cant believe Landrover send them out with such a poor state of tune... it feels like a 3 Litre has been put in it now and not a spanner or screwdriver was used!!! magic!

John...