300tdi poor power still a problem at low revs

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I've had trouble with mine in the past that took ages to get to the bottom of. I landed a new FIP for a decent price which did help things as mine was iffy from the start, but it turned out to be a cracked head.
Luckily being HGV techy I've got plenty of test gear on hand, all apart from a compression tester. I did sniff tests on it, checked timing, DTI timed it etc. It drive reasonably well under most conditions but it had random attacks of smoke and rough starts then all would be well. I'd previously rebuilt the engine, and the head was all done for me by "a specialist" hence why a head problem was pretty much ruled out from the start.
Is had enough one day and decided for what time it takes, the head was coming back off to be checked and pressure tested by a company I know do a good job, sure enough it was fooked. ****ed off don't come into it, but at least I had an answer. A proven good second hand head was fitted and she's been like a watch ever since.
sorry for the long reply but I feel your pain, all I would say is like others have said, get compression test done, and sniff test for piece of mind if nothing else. moral of my story is, trust your own experience and knowledge and don't always believe the so called "specialists"
 
300tditoy said:
I've had trouble with mine in the past that took ages to get to the bottom of. I landed a new FIP for a decent price which did help things as mine was iffy from the start, but it turned out to be a cracked head.
Luckily being HGV techy I've got plenty of test gear on hand, all apart from a compression tester. I did sniff tests on it, checked timing, DTI timed it etc. It drive reasonably well under most conditions but it had random attacks of smoke and rough starts then all would be well. I'd previously rebuilt the engine, and the head was all done for me by "a specialist" hence why a head problem was pretty much ruled out from the start.
Is had enough one day and decided for what time it takes, the head was coming back off to be checked and pressure tested by a company I know do a good job, sure enough it was fooked. ****ed off don't come into it, but at least I had an answer. A proven good second hand head was fitted and she's been like a watch ever since.
sorry for the long reply but I feel your pain, all I would say is like others have said, get compression test done, and sniff test for piece of mind if nothing else. moral of my story is, trust your own experience and knowledge and don't always believe the so called "specialists"
Click to expand...


Thankyou for the reply mate. Im going to have to try and lend a compression tester then i think, and see what each cylinder is reading and then go from there. Hope its not the worst
 
Dont spend any money just try the wheels first, got to be worth a go, the time you have spent typing replies you could have done it.
Always try simple stuff first.
 
Yes I reckon they are, thats why I said change them to see, that way you can answer the question 100 percent.
 
We all bombard you with suggestions the easy and straight forward ones need addressed first before jumping to worst fears
However if you've ran this tyre size a while and all was well before then the issue is elsewhere or as stated before highlighted by those big wheels
 
Hi all
Apologies for being a nightmare with land rover faults. But it's all good fun and a learning curve I really enjoy.#

Right, I'm digging up this thread. Because my dad has bought a 300tdi defender. With 40k more miles on the clock. The engine is far superior to mine. I'd lived with the lack of power since this thread ans thought it was natural due to not finding the problem.#

Well I was very wrong. Every 300tdi I've been in now has far more power than mine. My dads pulls from lower revs in higher gears. Lots of torque as the 300tdi is well known for. The power on mine comes in like a 2 stroke engine. Poor untill it's reved and the turbo is well spooled up (can hear it). Even very small loads in the back are noticeable on the engine. Also, mine is much more noisy. It has like a knocking noise from the top end. I always assumed it was diesel knock. But now It's putting towards internal issues.

Anyway, I decided it was about time I got to the bottom of the problem being as I knew something was definitely not right. So I compression tested the engine and here are the results:

Cylinder 1: 340 psi
Cylinder 2: 390 psi
Cylinder 3: 363 psi
Cylinder 4: 363 psi#

I then put a few squirts of oil down the bore of cylinder 1. And a reading came back of 470 psi. Not sure if I used too much oil or not. What do you guys make of these results? Are they showing a fault? I know that adding oil and if the reading is higher it's down to poor rings. But this problem is deeper than that I beleive.#

Over the months I've checked things:

-FIP Vacuum pipe from turbo is fine.
-Boost diaphragm fine
-Turbo play is equal to another well powered 300tdi
- all filters new and 15w40 oil used to reduce knock. Unsuccessful#
- cambelt replaced due to leaking crank seal (not My work) and I'm 100% certain it's timed correctly.#

Can anyone shed any light? I must admit I'm not familiar inside the engine. But would be willing to give it ago.#

Thanks alot
 
i'm not ace either. but they are all within 10% of the mean so seem fine to me.

when you add oil you are meant to use the same amount for each one
 
Something isn't right in the engine trax. It's very knocky.

I've been advised to slacken the injectors off one by one. What does this gain? What am I looking for?
 
ONE LIFE LIVE IT. D90 said:
Something isn't right in the engine trax. It's very knocky.

I've been advised to slacken the injectors off one by one. What does this gain? What am I looking for?
Click to expand...

if it's knocking then they are probably thinking bad injector. slacking it off will stop it working and the knock will go.

you could youtube a clip of it knocking
 
trax said:
if it's knocking then they are probably thinking bad injector. slacking it off will stop it working and the knock will go.

you could youtube a clip of it knocking
Click to expand...
Ahh I see. So I should slacken the union on top of each injector one at a time? Slacken or totally undo? Treating it abit like a brake bleed nipple?
Excuse the stupid questions, never done this before.

I'm going to get my brother to sort me a video out of it knocking. He's got a posh camera so hopefully that will show the issue better.

After doing some research it sounds like it could be diesel knock.
 
ONE LIFE LIVE IT. D90 said:
Ahh I see. So I should slacken the union on top of each injector one at a time? Slacken or totally undo? Treating it abit like a brake bleed nipple?
Excuse the stupid questions, never done this before.

I'm going to get my brother to sort me a video out of it knocking. He's got a posh camera so hopefully that will show the issue better.

After doing some research it sounds like it could be diesel knock.
Click to expand...

crack the nut. if you undo it you'll be covered in diesel :)

one at a time, crack, listen, tighten.. neeeeeext

if it's a good one then the engine will get rough. bad one, shouldn't make a difference (or will not knock)
 
trax said:
crack the nut. if you undo it you'll be covered in diesel :)

one at a time, crack, listen, tighten.. neeeeeext

if it's a good one then the engine will get rough. bad one, shouldn't make a difference (or will not knock)
Click to expand...
Thanks mate. So cracking the union/nut slightly will prevent that injector from supplying diesel? Like half a turn?
I know these are stupid questions. But I genuinely don't know about this. Surely cracking it off diesel will go everywhere but the Injector will still get diesel?
 
ONE LIFE LIVE IT. D90 said:
Thanks mate. So cracking the union/nut slightly will prevent that injector from supplying diesel? Like half a turn?
I know these are stupid questions. But I genuinely don't know about this. Surely cracking it off diesel will go everywhere but the Injector will still get diesel?
Click to expand...

yup, you'll soon tell as the engine will be all arrrrrg i'm not happy ;)

the injector needs a certain amount of pressure to pop. by cracking the union, not undoing it completely, you are relieving the pressure so it doesn't get enough to pop (or at least properly).. rendering it disconnected. you will get some spillage, but it's only just loose on the thread so it's not too bad. mop it up.
 
trax said:
yup, you'll soon tell as the engine will be all arrrrrg i'm not happy ;)

the injector needs a certain amount of pressure to pop. by cracking the union, not undoing it completely, you are relieving the pressure so it doesn't get enough to pop (or at least properly).. rendering it disconnected. you will get some spillage, but it's only just loose on the thread so it's not too bad. mop it up.
Click to expand...
Perfect!

thanks again trax. I'll give this ago hopefully tomorrow night. I'll report back with my findings. Got my fingers crossed it's the injectors.
 
if you suspect an injector knocking, then it will probably be shooting a straight jet of fuel instead of a mist.

this may give you a lil puff of smoke out the back.

you can also take the injector out, spin it over, hook it back up and watch to see if it sprays funny.

be careful it shoots out at a decent pressure, don't let it aim at you.

or you can buy a pop tester on ebay or take it to a place that tests them :)
 
trax said:
if you suspect an injector knocking, then it will probably be shooting a straight jet of fuel instead of a mist.

this may give you a lil puff of smoke out the back.

you can also take the injector out, spin it over, hook it back up and watch to see if it sprays funny.

be careful it shoots out at a decent pressure, don't let it aim at you.

or you can buy a pop tester on ebay or take it to a place that tests them :)
Click to expand...
Slackened off each injector this afternoon one after another. Each one gave virtually identical results, made the engine hunt and hesitate. The flow to each injector pipe also seemed identical.

Back to the drawing board haha.
top drive said:
get a clear bottle and stick the injector inside that to see the spray pattern......poke doing it to atmosphere......
Click to expand...
 
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