110 TD5 intermittent hesitation

Hi. My new to me 2002 Defender 110 TD5 has recently started to occasionally hesitate whilst running. Sometimes it's just a little miss, but occasionally there's quite a big jerk. The car has just had a service with new fuel filter. The red plug at the ECU is clean as it is in the cylinder head. Nanocom shows no faults (other than an air con fault which is strange as it doesn't have air con). There is more often than not a distinct diesel knock, but sometimes this disappears and the engine is quiet for a few seconds. The car has done 155,000 miles but I believe a replacement engine was fitted at about 85k (but not sure if this was a new engine or a used one, so don't know the true mileage of the car). Also at times the car doesn't like to start on first turn of the key but will fire immediately on second turn. Any ideas where to start looking?

ignore aircon fault- says that when not fitted

possibly injector washers and o rings

jonny2tanx said:

The red plug at the ECU is clean as it is in the cylinder head.

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Could you clarify this bit ^^^^^^^^^


It doesn't make much sense as the ECU and infamous red plug are normally both under the drivers seat. Unless a harness extension has been fitted. Also its the injector loom that is under the rocker cover.
If I recall correctly the Disco TD5 has the ECU at the rear of the engine compartment. Was the replacement engine from a Disco?

As Fanatic says Nanocom will show AC fault if there is no AC

It's your call. But before replacing your injector seals you may want to check out a few other bits first. I always start with the cheepest/easiest/most likely first.

Intermittent random faults are normally electrical and a real PITA.

Here's a list of stuff to check.
Main relay
Ignition Switch.
Fuelpump and relay.
Immobilser live feed.
Red and Black ECU plugs red one for oil BOTH for LOOSE pins

Oh and of course injector seals

NOT an exhaustive list I'm sure and it's entirely upto you to decide which is the cheepest/easiest to do first

Also it's not unheard of for various cables to chaffe and or become brittle between any of the above mentioned components.

If you're anywhere close to me. I'm more than happy to help

Thanks for the suggestions. Would there be any other symptoms if the injector seals had gone? Reason I ask is that I once had a seal go on a Mercedes 320cdi and it filled the car with fumes, but having said that the injectors weren't under the rocker cover on that car.

BD - The ECU is under the seat. hat I meant was both ends of that loom are clean and free of oil -I used to have a Disco TD5 and had oil in that one so have an idea what to look for there. Unfortunately not anywhere near you and am going to be even further away tomorrow - meant to be catching a ferry Saturday evening for a 1600 mile trip! Why do these things always happen at the most inopportune time?

Injector seal failure may also dump deisel into your oil.

So rising oil level and or smell of deisel on dipstick.

Can't think of any other symptoms at the mo

poor starting is a usual injector seal failing fault, as is white smoke on start up

No rising oil level and no white smoke on start up. I've bought some injector seals 'just in case' it gets worse. If I took the rocker cover off would there be anything to see if theres a slight blow by? I know my Merc had loads of crud around the injector but that had well and truly gone

no, not normally any visual sign, yours could be a failing fuel pump or clogged filter but you've changed that

When does the hesitation start what speed and revs ?

Jaswilliams said:

When does the hesitation start what speed and revs ?

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Sorry, was on a ferry just arriving in Dunkirk when you posted your question, and have had no internet connection until now. Have just done slightly over 1100 miles in less than 24 hours and the jerking has decreased a bit but mainly appears to be when going uphill. Even though there is some hesitation then it doesn't prevent you accelerating up the hill - it just has a little think about it first and sometimes during. Having said that my route so far has been relatively flat and faster compared to my usual route for the car which has gradients taken at a slower speed. Please forgive me if this is confusing - just enjoyed a few bottles of Polish beer before replying.

In summary, it appears to be at slower speeds on uphill gradients at lower throttle openings. Good job where I'm headed for tomorrow is relatively flat!

The car did throw up another issue though - a noise that sounds like a worn speedo cable behind the dash - only there is no speedo cable on the TD5. Girlfriend said 'Just ignore it' and then proceeded to drive the car at a 'challenging' speed for quite some time, while I had a little nap.

Sounds to me like a stuck wastegate very common on the td5

Jaswilliams said:

Sounds to me like a stuck wastegate very common on the td5

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Thanks for the suggestion. I'll take a look, when I can get a minute. And when I can get somewhere near my tools! They are buried somewhere in the back of the car under a mound of baggage stuffed to the roof! We always travel light!

Hi Jonny. Did you get the bottom of your car's problem? It sounds very similar to what's happening to my Disco 2 TD5.

dc60 said:

Hi Jonny. Did you get the bottom of your car's problem? It sounds very similar to what's happening to my Disco 2 TD5.

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Shhhhhhhh the car may hear you. Touching everything wooden it hasn't done it for ages, and the frustrating thing is I don't know what happened to change things. We did a 4000 mile round trip over the summer and I used premium fuel whenever possible, although did get some dodgy fuel too (but at less than 50p a litre ) when I used a double dose of Millers fuel additive to increase the octane rating, driving the car at challenging speeds for a fully loaded brick! Maybe it needed a good thrashing to sort it out!