Vibration at 2500

[brendo]

Hi guys I have a qd32 with a turbo on it and just in the last few weeks it has start to have a vibration at 2500 it's only at these revs that it makes it and I can't seem to find it and was just wondering if anyone would have any ideas I had the lower control arm brake a about two months ago and replaced all those parts cv,arm, ball joint and I thought it might of been some thing around that area but check them all tight

 

[Old.Tony]

If it's at 2500rpm in any gear, it'll be something between the engine and the gearbox input shaft. If it's at 2500 only in one specific gear, it'll be something between the gearbox input shaft and the wheels.

Have to start there. Ordinarily I'd have jumped at "clutch" but yours is a D22. Doesn't mean it can't break a thrust bearing lifter or suffer from a partial deformation in the pressure plate, but the only way to point to that is to know a little more about when the vibration occurs.

 

[brendo]

thanks tony It's in every gear only when I I'm accelerating if I'm just cruising in that gear it seems to be fine I need to replace the centre bearing I have a new one to replace it with I was thinking it might be that but was not sure if it could be something els it's been stuffed for a while I think but has not made and noise or vibrated.

 

[Old.Tony]

Might be an idea to check the cooling fan. There have been a few reports of cracks developing at the base of the blades, and that could cause the blade to flutter producing vibration. Depends how bad it is, of course.

I doubt it's your drive shaft if it's happening at 2500rpm in every gear. It'd have to be forward of the gearbox input shaft - so thrust bearing, pressure plate, clutch and onward.

 

[brendo]

Ok thanks I'll have a look at the fan and see is there anyway of telling if it's any of the others with out pulling the box out

 

[brendo]

I forgot to mention that is more of a vibration noise I can't feel it to much at all just the sound

 

[Old.Tony]

Then it does point to the fan. Take a good look, flex the blades and examine them. Make sure there are no chunks removed from the thing too!

 

[brendo]

Ok thanks tony will check that tomorrow after work

 

[brendo]

Ok had a look at the fan can't see anything wrong with it I tightened up some bolts that we're lose and took it for a drive and it only seem to make the noise in 4th gear now

 

[Old.Tony]

The same noise, or is it different?

Just to make sure, when the noise starts happening, can you keep the car at that speed and depress the clutch? Does the noise go away?

 

[brendo]

Same noise I'll try that if I drive it tomorrow. When I get to 2500 and I take my foot off it stops The other thing I noticed was the radiator seem to move a bit the rubber gromits the are on the top of it the part that sticks threw them seems to move abit not shore if it's normal or not

 

[Old.Tony]

The radiator should have a bit of movement but it shouldn't be a large amount, the engine is vibrating and pulling on the hoses which should make the radiator move a little bit. Are we talking about a minor gentle movement or a rattle-the-bars "let me out of here!!!" kind of movement?

 

[brendo]

Not much at all maybe a mil or 2

 

[Old.Tony]

I'll kick mine over later and take a look. I don't think mine moves "or two" mm - more like a minor vibration if anything, we were looking at it with a radiator specialist when I was diagnosing my cooling issue (turned out to be the fluid couple) we specifically looked at the top tank, because it had been replaced - and I don't recall much movement at all.

Have some cable to install first, need more heavy power to the rear, plus I have a couple of light bars to install (two small ones 3340 lumens, one larger one 10320 lumens). In among that, I'll take a look!

 

[brendo]

Ok thanks tony Sounds like you have a fair bit to do today yeah I want to start to get more lights on my I had a set but when the arm broke I had to jack it in a not normal place and the high lift jack slipped a bit and broke one

 

[Old.Tony]

I've finished the extra cabling and I've tested it, and it's a good thing I did it. The original installer of the electrics in my car did a cable that could handle the 15A or so that was needed down the back (7A charger - call it 8A give or take a little plus 5.5 to 6A for the fridge). I was seeing voltage drops when driving a 600W inverter to power the fridge (about 350-380W needed). Voltage at the rear of the car was falling from 14.4V to 10.9V and in the caravan from 10.9V to 10.5V. Shows that under a heavy load, the adequate cabling was way insufficient. During the work, I noticed that the earth wire was overheating and had started eating its way through the insulation. I've fixed that - I can now safely carry 112A (two 56A 8Ga cable runs with earth as well) all the way, and now my voltage at the fridge is marginally under 13V with the engine idling. Resolved, on to the lights!

While the engine was running I examined the radiator. Mine sits dead still. I can move it about 1-1.5mm each way, but it doesn't move on its own. My engine wobbles a bit, and both idler pulleys were squealing away (Silicone Lube fixed that), but the radiator sits there like a stone.

How are your radiator hoses? Hard?

 

[brendo]

That's not good at all mate at least it sorted now yeah I had another look at mine and it doesn't seem to be moving enough to make noise and I took it for a drive but forgot to. Try and push the clutch in at the speed I'll be driving it later tonight and will see it I did back of when got to the revs and it stopped so I'm stumped

 

[brendo]

Ok so drove the car last night and today and got to 2500 and pushed the clutch in in. 4th gear and the revs dropped and the sound stopped so I tryed the same thing but left my foot on the gas and keeled the revs at the 24 to 2500 and noise was still there so I'm not sure I looked under it today and wheat over all the bolts and everything is tight the only thing that is lose is the centre bearing in the tail shaft so I'm stumped if it not that

 

[bods]

if it does it with no load on the engine at that rpm i'd look at bearings, could be the alternator or one of the pulleys, possibly water pump bearings too?

 

[brendo]

Ok thanks I'll have a look at them too when I get a chance I just can't work out why it dose it only in 4th and no other gear