Engine wobble (stupid query probably)

HauptRenate

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Err, everybody.
What makes an engine wobble? I mean, it is not static, should it be as still as a sleeping baby? When you lift up the bonnet and see your engine moving does it mean that the injectors need to be looked at?
I was just wondering because it seems to activly chug away to itself, and when one revs and puts her foot down it kinda jumps. It's as if the whole car jolts a bit, is this normal for a 1991 'J' reg turbo diesel?
To my inexpert eye its always done this.
I've checked the engine housings and these are fine.
Cheers
Renate
 

Crispin

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I've often seen that after engines have been driven too fast. Normally in excess of of the legal speed limits ;)

Sorry, could not resist a joke :lol:

The vibration is because the engine is not a balanced load and is spinning around. The crank and pistons are all out of balance and anything spinning which is not balanced will vibrate.
The lurch you see when you open the throttle is the inertia of the crank [s:3f5zzj8j]/ block[/s:3f5zzj8j] when the [s:3f5zzj8j]engine[/s:3f5zzj8j] crank starts spinning faster. The friction between the piston rings and cylinder walls increase the lurch. As the inertia is overcome, it will (mostly) return to it's normal position.


A layman's explanation - someone more technical may come along and explain it better.
 

Paul

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Could be the idle speed is too low.
 
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Dave Docwra

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Valve clearance's, engine mountings, fuel issues, front crank pulley, flywheel & attached items, twisted/damaged crank are some of the most common problems.
 

HauptRenate

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Guys
Sounds serious... now you can't be expecting me to take out the entire engine and have all its bits sorted - or, you are just trying to scare me, either way I'm not going to accept this.... so please be a bit more specific.
Someone mentioned it might be because my fuel injectors need to be looked at - £22 per injection after its been whipped out and sent away.
Engine mounts are fine, and it has been this way for a long, long time and hasn't so far compromised anything to my knowledge, and in actual fact, just recently someone who has an 'ear' for engine sounds listened for a long time (its his job), had me change gear a few times, drove it in all the different gears (except neutral of course) slow idled, fast idled, had the bonnet open and he stood his ear as close as he could safely get to the engine whilst I revved the hell out of it - conclusion, the engine
'is as sweet as a nut' [unquote] he couldn't fault it at all.
So are you saying also that the MOT should have picked up on this if there was something seriously amiss with it? the mechanic tooklong enough to 'examine' the engine workings (no he;s not the one with the 'ear' for the job, and the 'ear' for the job isn't Julian.
Renate
 

HauptRenate

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Julian adjusted the engine idle Paul, so this should be okay, as I trust Julain V (I've known him long enough)
Yeah, yeah Crispin! I'll let you off, I took the joke the way it was meant!
Regards
Renate
 

Andrew Prince

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:lol: You're being wound-up here! It's the gyroscopic effect of the crank turning that makes the engine lurch when you blip it. Crispin's explanation would confound Mr. T himself :laughing-lettersrofl:
 

Andy Harvey

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Often why high performance engines have torque dapers on them to control the twist - caused by the effect ofthe engine turning - every action has an equal and opposite reaction etc. Engine turns clockwise, engine will tend to twist anti-clockwise on it's mounts. The effect carries on all the way down transmission which is why on Drag cars they have to put all kinds of extra anti this and that bars on the axle to stop it spinning away like a top on the propshaft axis.

It's also the same reason that heicopters have tail rotors (or contra-rotating second rotors like the chinook) otherwise they would spin themselves into the ground.
 

HauptRenate

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Thankyou Andrew for this 'sensible' explanation!
and thankyou too Andy for yours!
and thanks Ecky!
I'm feeling much better now...
Renate
 

Chas

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HauptRenate said:
I'm feeling much better now...Renate
It's amazing what a few JD's and Coke will do :lol: :lol:
Chas
 

Andy Harvey

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You should have seen how the small block chevy used to move in my old Camaro - used do it at the traffic lights just to make the body move - all that power and all. Knackered engine mounts didn't help much though.
 

Chas

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I used to own a Daimler Dart SP250 with a 2.5 ltr V8, that almost turned somersaults at the lights if I revved it :shock:
Chas
 

HauptRenate

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Err, Cossack I haven't had any JD and coke today
Err, confuse you in what way Locrep? methinks I'm the one that's confused!
Guilt complex - I used to rev the engine whilst at traffic lights, because when it moved on revving, it would be noticed...
Not really feeling that much better, I'm still unhappy about what it might be though, but the positive comments did help (perhaps this is what you are referring to Locrep?), at least my mind was put to rest a little.
Maybe I was just overreacting, but the thought of having the engine totally and completely overhauled or maybe parts of it removed totally freaks me out, as I assume it will be massively expensive.
I have my insurance due this time next month, so yes, I am worried.
Renate
 

Dave Docwra

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No point getting freaked out until you know what is wrong, then again still no point after that either,
what confuses me is that you ask what it could be then make it out that it sounds like scare mongering,
then tell me/us you had someone look at it and they said it was fine, Julian V had worked on it & never
mentioned to you that it sounds a bit uneven & I have never met JV but I know he has a good reputation.

What are the positive comments?

What are engine housings?

It is obviously not a Fuel related fault as it was recently spotted going quite swiftly, even with steering
wobble.
 

Andy Harvey

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HauptRenate said:
Maybe I was just overreacting, but the thought of having the engine totally and completely overhauled or maybe parts of it removed totally freaks me out, as I assume it will be massively expensive.
Renate
With the 1HD-T if it sounds like a bag of nails then worry about it, if it doesn't then drive it till it does and apart from doing regular oil changes you don't need to worry untill it does sound like a bag of nails. With clogged injectors you will tend to hear the problem as well as feel it and with the BEBs you will hear a loud ticking just before it self destructs but if you've changed them then no issue.

If Julian V wasn't worried then i wouldn't be either.

Oh and Paul, Daimler Dart now that was one fine but seriously ugly motor - the 2.5 V8 was always better than the Rover and it's big brother the 4.7V8 in the Limos was also a peach of a motor.
 

HauptRenate

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Actually Locrep, it wasn't a 'steering wobble' you misunderstood me, that was fixed by Julian V's new prop shaft UJ on the Tuesday gone (last week), I'm talking about the vibration that is inherrent in the engine.
And I wasn't trying to confuse anyone! honest! I just asked for some idea what might make an engine wobble and you all scared me by giving me a long list of things that might be wrong with it!
How was I supposed to react? say, "okay, I'll whip out the engine then, no problem, and take out all its bits, its injectors, pistons, cylinders?!" how the h**l am I supposed to do that eh? with no tools, no expertise, no workspace, no garage, and no readdies?
Please, do enlighten me Locrep!

Yes, Julian V did say the injectors might need looking at and just suggested that I get the injectors looked at just before I leave the UK for Europe and North Africa again, for my next long stint. I did know this much, so I'm not toally brain-dead.

And, thanks for your comment Andy H, exactamon! I would be seriously worried if it sounded like a bag of nails!

R
 

Paul

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Maybe a go in a few other peoples 80 would help?
 
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