Engine vibration 1HD-T

[StarCruiser]

I don't know about leaking valves on Toyota engines but on LR diesel they just ran rough with no other symptoms.

Hmmm, now you've got me thinking Frank. If that's the case, then it's certainly worth checking. I'll have to have a read in the FSM I think and dust off my feeler gauges, though I do recall a special tool and shims and things so it may not be that simple. With that set up I'm guessing there's no hydraulic tappets.

What you're saying does make perfect sense AND S&S did say injectors or a valve. And I did have more of a sucking sound from one cylinder under compression when I did the BEBs and turned the engine round on the pulley.

Took it for a run last night and the engine seemed a little more responsive, or maybe that was me. However it did seem a tad low on power as it started falling back climbing the hills. Could have been the weather of course.

More head scratching needed and a look at those valves.

 

[frank rabbets]

Just make sure there is clearance on each valve rather than adjust them. That would rule out vibration caused by a stuck open valve. Unless one is wildly too large a gap.

 

[StarCruiser]

Ok, thanks Frank, there's probably going to be a clearance value somewhere, I think it may even be on my rocker cover. I suppose it's possible to have a weakened or broken spring which I expect is a pig to find without taking the head off.

It's certainly different. There is, I think, more of a 'ping' from the injector pipes indicating the pressures are good and that all is well there though I haven't yet listened to them in detail. It just sounded different with the bonnet up.

Back on it tomorrow.

 

[frank rabbets]

If your valves all have clearance then I guess you need a gauge compression test. One thing I don't have is one for diesel engines.

 

[StarCruiser]

Well, I didn't get back on it 'tomorrow'. In fact I've not had the chance to look at it at all. However, today, during marshalling an off road day, I noticed a slight wisp of white smoke while idling. A quick rev up to blow out the cobwebs, and it's still there.

I'm convinced the smoke and the vibration are linked. I have some diagnosing to do.

What's sitting in the back of my mind is the 'Darth Vader' sound from cylinder 6 while manually turning over during BEB replacement. Making me think a broken piston ring, which I really hope not. Not jumping to conclusions here, I suppose it could be a valve.

Must start the testin' and stop the guessin'.

 

[Shayne]

Wish i could introduce you to an uncle of mine he's a great mechanic and he's been blind for 30 years or more . All my fears are gone because his verdict on my truck was - best sounding motor he has heard for a while but there is a leak in the intake somewhere near the front left corner of the truck , turned out to be the foam doughnut seal around the pipe from the air box into the wing was split . He's a bit far away to help unfortunately .

 

[StarCruiser]

Thanks Shayne, he sounds like a real gem. It will not be long before such experience is lost from this country.

 

[frank rabbets]

Time for a proper compression test after checking the valves have clearance. Good luck.

 

[StarCruiser]

I agree Frank. I need to get onto it.

 

[StarCruiser]

Right, finally got the time and the weather to look at my valve clearances (boy do I know how to live now!!) and the results are in, as follows.

From flywheel, in thou.
1,012 dead
2,004-005
3,012-013
4,0.04 dead
5,012-013
6,006-007
7,014 dead
8,006 dead
9,012-013
10,004-005
11,012-013
12,006-007

Where two sizes are shown, it means the smaller waggled about and 2 thou up wouldn't fit.

Now I know these should be done cold and I will check the last one again when it's stone cold tomorrow morning to compare, but would driving it off the drive, for 1 minute max and leaving it for 20 minutes then driving it back on for a minute then measuring the gaps after about 10-15 minutes getting the cover off, cock the readings up?

I see that they should be:-

Inlet: 0.15 - 0.25mm or 0.006 - 0.010in
Exhaust: 0.35 -0.45mm or 0.014 - 0.018in

Going by this, all my valves have closed up and could possibly be my problem (hope and pray fingers crossed)?

The questions I now have are:-

If this IS the problem, and there is clearance (as shown above and not no clearance at all), would it cause my vibration AT COLD as much or more than when hot? I'm thinking this throws valve timing out and is not simply letting gasses by.

Do I just do the shims or do I need to take the head off and regrind valves?

Your thoughts as always welcome.

On to compression test next?

 

[frank rabbets]

Altering those clearances to the correct ones will make no difference at all. .

If those clearances WERE the problem you would find the engine would run OK when cold then vibrate when hot due to lack of compression caused by a minus clearance on the tightest valves you have. I just don't think they are far enough out.

I would try the compression test next.

It will be interesting to know whether your clearances are different in the morning. By cold they mean not hot as in fully warmed up to running temperature.

 

[Rarf]

A new injector cured the problem, to save having all the injectors serviced/tested to eliminate the possibility of a faulty injector, it maybe worth considering dropping the exhaust manifold back to show the individual exhaust ports, one might show up something obvious like being coked up or slightly damp etc, pointing to a problem on a particular cylinder.

 

[StarCruiser]

Altering those clearances to the correct ones will make no difference at all. .

If those clearances WERE the problem you would find the engine would run OK when cold then vibrate when hot due to lack of compression caused by a minus clearance on the tightest valves you have.

That was exactly my thought, hence the question.

I will check at least one in the morning, and post any difference out of interest. I didn't expect there to have been much if any change over two minutes or less of run time.

I also got the Darth Vader breathing sound as I turned the crank, again only really from cylinder 6……I really don't want it to be a ring…[emoji22][emoji22] but that was my first thought when I heard the sound while changing the BEBs.

Compression test next. I'll try the electrical version first.

 

[StarCruiser]

Hi Rarf, welcome and thanks for that thought, alas I had all 6 injectors serviced and reconditioned a month or so back and although they needed attention, the recon didn't cure the vibration.

I do have all manner of filters to check, but the thing goes so well (and better now the injectors have been done) I find it hard to believe it's a blockage anywhere causing fuel starvation.

My money's on a broken ring as there's the merest hint of white smoke when idling, difficult to see. And there is a bit of crankcase pressure, but I don't know how much is good and how much is too much. Unless I could compare it to an identical but perfectly good engine, it's going to be difficult to tell.

 

[StarCruiser]

Ok, remember that Darth Vader sound I was describing, well I managed to record it but it's got a lot more going on on the sound track and the video is a bit boring as I had both hands turning the crank but, well you did ask for it so here goes…

https://vimeo.com/135145769

I didn't realise I could post video using Tapatalk[emoji4]

Just listen in the background, I haven't a clue what all the other noises are, but they aren't relevant.

 

[frank rabbets]

Sounds like gas escaping into the crank case. A healthy cylinder will do it so I can't hear if it is more pronounced on just 1 cylinder.

If you can crank the engine without it firing you should easily be able to hear the relative compression strengths of each cylinder :- jer jer jer jer jer jer = 6 good ones :- jer jer jer jip jer jer = 1 weak one.

Some of the 6 cylinder engines I've worked on played very amusing tunes.

I think you can stop the 12 valve engine from firing by taking the wire off the fuel pump. Someone on here will know.

 

[StarCruiser]

Thanks Frank. I have done this one but at the time I couldn't hear a definite difference. The scope test I can do will do this electrically producing a trace from the alternator.

It's only a matter of time before I do a proper mechanical compression test. I'm just dreading pulling it all apart, well dreading the cost more than anything TBH.

 

[StarCruiser]

Ok, tried the feelers in No10 valve just now and it's still 004-005 as 006 won't fit but 004 waggled about. Also No 7 is still 014 dead, so I think it safe to say that all valves will be unchanged.

 

[frank rabbets]

Yes they don't tell you to check clearances in winter or summer so there has to be a big change in temperature to affect the clearances.

I would defo get a compression test to prove one or more weak cylinders before starting to take the engine apart.

 

[StarCruiser]

Oh don't worry, I'm in no rush to take the head off and pull it all apart. After rebuilding the front axle and reconditioning the injectors the budget is spent and I just know without looking that the bits aren't going to be cheap[emoji20]