TD5 rough running

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jsbholden

New Member
Posts
260
Location
Matlock
My TD5 runs rough between 2000 to 2500rpm and is engine related as it does it when stationary, although it is amplified under load. Below 2000rpm it sounds a bit rattly, over 2500rpm the engine is strong and pulls like a train with no problems. It came on suddenly when driving on the M25.

So far i have

Replaced the injector loom as it had oil getting to the ECU, although this didnt cause a missfire

Replaced the exhaust down pipe in case the flex joint had gone

Changed all the filters and fuel pressure reg

Checked the wastegate arm (moves OK with a pair of mole grips)

Replaced the intercooler pipes.

I have also checked the crank pully for play and it has a very slight wobble at idle.

My gut feeling is that it's something electrical as some days it's worse than others. I've plugged it into my nanocom and its not showing any faults and the cyclinder ballance looks OK.

Its getting to the point now where the car is horrible to drive (being an auto it tends to sit in the 2000-2500 rev range). So before i put it on ebay I wondered if you guys had any ideas on what it could be
 
Have checked the ECU inside and it was dry. Did wonder about the fuel pump but wouldnt it run rough throughout the rev range?
 
Try the crankshaft pulley again. It is a two-part DAMPER, and may be coming apart.

Check other things too, like alternator, fan, and anything driven by the belts.

It seems to be speed sensitive, so you are probably looking for a rotating part with wobbly bearings or out of balance.

Do a careful check on the engine mountings just in case one has split or gone soggy on you.

CharlesY
 
Will start stripping it down tonight. How's the best way of testing the crank damper? or will it be obvious if it's knackered?

I'll also record the fuelling again on the way home from work and post the readings tonight just incase someone can spot something thats not right there
 
Hve taken the belt off (with difficulty as i cant find my spanners for the fan!). Have found:

aux belt tensioner below alternator has a play in it and when spun sounds like the bearings are shot

Power steering pump has slight play on the pully (up and down), when being rotated appears to have some slack in it and makes a metal to metal clunking noise

The crank pully appears to be ok but will need to get the fan off for a closer look and engine mounts look ok but the drivers side one is sitting slightly lower

I ran the nanocom on the way home and the output file doesnt show anything too worrying appart from masssive cylinder imballance on over run i.e.

cyl 1 = 1
cyl 2 = -5
cyl 3 = 17
cyl 4 = -9
cyl 5 = 12
 
just worked out how to get the numbers out of nanocom!

Accel:

Road speed = 44
Engine speed = 2391
Idle speed err. = 1495
Battery voltage = 14.349001
Pot trottle 1 = 1.788000
Pot trottle 2 = 3.297000
Pot trottle 3 = 3.443000
Pot supply = 5.037000
Ambient pressure = 100.959998
Air flow = 438.500007
Air inlet temp. = 19.700000
Air inlet press. = 191.729996
Coolant temp. = 75.000001
Fuel temp. = 52.700001
EGR modulator = 0.000000
EGR inlet = 22.589999
Turbo Wastegate = 22.589999
Power balance 1 = -3
Power balance 2 = 5
Power balance 3 = 2
Power balance 4 = -3
Power balance 5 = -1

Decel:

Road speed = 47
Engine speed = 812
Idle speed err. = 26
Battery voltage = 14.349001
Pot trottle 1 = 0.716000
Pot trottle 2 = 4.369000
Pot trottle 3 = 0.000000
Pot supply = 5.037000
Ambient pressure = 102.209998
Air flow = 62.800001
Air inlet temp. = 18.500000
Air inlet press. = 101.979998
Coolant temp. = 64.700001
Fuel temp. = 46.300001
EGR modulator = 0.000000
EGR inlet = 0.000000
Turbo Wastegate = 0.000000
Power balance 1 = 6
Power balance 2 = 11
Power balance 3 = -6
Power balance 4 = -6
Power balance 5 = -11

Just looking at the pot values, shouldnt the value of the 3 pots = pot supply?
 
Just looking at the pot values, shouldnt the value of the 3 pots = pot supply?

No. The value of 1 is taken off the value of 2. If you add these together they will give you the value of 5 you want. The value of 3 is the one that gets me. On some vehicles it appears that 2 is taken off 3. Others it appears it's added. The values also change dependent on vehicles too. The TD5 has values of around 5. The new puma engine has values of 30.
 
look at post 14.;)

:D:D:D

I'm doing my best to get it!



The engine (any engine) can do this for two reasons:

1 there is something rotating or reciprocating which physically is or goes out of balance, and at some particular speed (the first harmonic) it really goes wild and starts lashing about. At TWICE that speed you might notice it again, but probably not so badly.

2. the engine is misfiring somehow, and making you feel the roughness.

Let's rule out 2 meantime, because you say it's actually running quite well.

Back to 1.

Start the engine, and sitting there parked in neutral, very slowly bring the engine speed up towards the bad range. It either will or won't set the vibrations going. If it does on what is very light throttle, you can be practically sure some rotating component is off-balance - like a two-part silly-arse flywheel for instance, or a crankshaft pulley-damper. If it was mine, I would hunt down rotating parts first. Some quite small part (like an alternator) could make a quite big vibration if it went right out of balance.

Next, if it vibrates when you run the revs up, take off the belt and try again. If it now doesn't vibrate, one of the things the belt drives is the likely culprit.

It's a bit of a guessing game.

If you cannot make it do this when the car is sitting parked, drive it again, and see if it happens at those revs in the gears, 2nd, 3rd, 4th, 5th, or if it only happens at a certain road speed. You see where we're heading? If it happens in most of the gears it's the engine. If it happens only at a certain road speed it's probably transmission or drive-train or hubs related.

Let's keep on the case because I want your Novacom thing.

I would pay for it ....

CharlesY
 
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I'm not a TD5 owner yet (hopefully very soon!!) but I've heard of some rough running being caused by the MAP in the inlet manifold?? being caked in crâp so not working correctly. A good clean might be called for.

Also the same basic idea with the MAF - these apparently can become contaminated and give bad info to the ECU - switch cleaner is your friend.

Good luck

Dave
 
I'm not a TD5 owner yet (hopefully very soon!!) but I've heard of some rough running being caused by the MAP in the inlet manifold?? being caked in crâp so not working correctly. A good clean might be called for.

Also the same basic idea with the MAF - these apparently can become contaminated and give bad info to the ECU - switch cleaner is your friend.

Good luck

Dave

Why don't you keep your smart suggestions to yourself till I've got that Novacom from him?:mad:

CharlesY
 
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