Bottom end making expensive sounding noises

[Dutch24V 0]

I have just changed the serp. belt tensioner as the bearing was on it's last legs. The tensioner is quiet now, but I can now hear more worrying bottom noises.

 

It sounds like a bearing of some sort and it's a very deep nocking/clicking that comes from the block itself. It's more noticable on the side of the airbox, down by the crank wheel. I know the water pump is down in that area, but the way it seems to resonate through the block itself makes me think it's a much bigger problem than the water pump bearings. I hope I'm wrong! :(

 

Any thoughts anyone? I'm too scared to drive her now as I've had a piston blow a 2 inch hole in a VR block before!! If it is the crank bearing? - how big a job is that to sort?

 

Dutch

[Kevin Bacon 5]

The water pump is cheap enough to try one and outrule it as the cause of the noise.

 

If it's not that or the PAS pump, then it might also be a worn bearing in the gearbox transmitting it's way through the block. It's difficult to pin point noises accurately without an automotive stethoscope type device.

 

As you say though, worn bearings in the block tend to emit a deep knocking. If you've got an oil pressure guage, you'll notice a drop in pressure if the main bearings have gone.

 

Mains need the engine out to change. Big ends can be changed in situ after dropping the sump. So if it is a bearing failure, pray it's the big ends!! Mind you, you're still not out of the water until you've checked for journal scoring. If the crank journals are scratched, forget it, fit a new block/engine.

[edd 0]

First thing to check is belt did you put a new one on. Had a similar clicking, knocking noise recently that was a bit of a worry since i'd had a full, engine rebuild. The PAS pump was changed cos thats practically the only part that hadn't been and the noise was still there. Anyway after a brief period of panic from myself regarding pulling the whole sodding block back out again Vince did a quick swap of belts just on the off chance and would you believe it noise gone.... and the belt looked immaculate by the way. Very odd but worth a check.

[edd 0]

though noise wasn't that deep... still worth a check!!

[Dutch24V 0]

Edd, no i didn't change the belt. I think it sounds too deep and mechanical to be the belt though, but will bare it in mind thanks.

 

It could be the PAS or water pump I guess. I'm going to get a stethoscope of some sort tomorrow and try to narrow down the area that's making the most noise. What ever it is it sounds like it has abit of weight behind it if you know what I mean hence if it breaks I think it'll do alot of damage!? :(

 

Kev, what exactly are the big end bearings? - are the main bearings the ones on the crank?

 

Dutch

 

PS, was nice to finally meet up over the weekend Kev, likewise Dinkus and Supercharged. Very interesting driving a tdi right-hooker and seeing under Kevs bonnet! :)

[Kevin Bacon 5]

Yeah good to meet you too mate, shame I was too busy to have a proper chat and take you out in my car etc.... Steve did a good job of keeping you entertained though and you've now had the rare experience of driving a TDI Corrado ;-)

 

My girlfriend lives in Harwich and I'm there a lot, so if you're ever there, gimme a bell/text and we'll meet up again.

 

Anyway, big end bearings.... they're the white metal shells that seperate the conrods from the crank journals. With the sump off, you can simply undo the conrod bolts and change the shells, but it's vitally important the crank journals are not scored. If they are, the new bearings will last a 1000 miles tops. Oil starvation mid bend is what kills big ends faster than anything else.

 

Main bearings...the VR is a 7 bearing crank and they basically hold the crank in place. The engine needs to come out to replace those.

 

When the engine is hot, big ends can be detected by that deep thudding and when you blip the throttle...if it goes r-r-raaaaaar, instead of, raaaaar (LOL!) and assuming there's no misfire, it's prolly the biggies. The momentary pausing (the r-r bit) is the slop in the conrods....it alters the CR slightly for a split second. It's easier to explain at the engine , LOL!

[Dutch24V 0]

No worries, was interesting anyhow. Hope you got your dash back together OK and Dinkus managed to get his radiator back in!? :)

 

I'm going to take the belt of and run her for a few seconds to see if the noise is still there. I'm hoping it won't be, thus pointing to either the PAS or the water pump if I'm lucky.

 

lol, I kind of get what your saying. I'll try and listen in more detail what kind of r-r-raaar noise it is tomorrow then.

 

Dutch

[CoxyLaad 0]

how about doing a quick test and firing the car up with no belts attached. That way the water pump will not be running, nor any of the other potential culprits. so if its still knocking, start praying!

[.Rich. 0]

I have a problem which sounds a little like this; my problem is the idler pulley on the waterpump where the alternator belt goes around. The bearings are shot and it rattles from side to side quite drastically and make a noise. I have a new one (£50) but ive not fitted it yet!

[Dutch24V 0]

Rich, that sounds like it *could* be my problem too, or something simular I'm hoping.

 

Is that an easy part to change?

 

Dutch

[Dutch24V 0]

Well, it seems to be a pump bearing of some sort as it goes when I release the belt tension :D

 

I'm going to remove the inside wheel arch and investigate further but presumably it's ok for me to drive short distances as whatever it is should not damage the engine if it breaks, or am I missing something hear??

 

Dutch

[.Rich. 0]

If it is your problem then yes its an easy part to change, its just an idler pulley (think they call it a 'v pulley') which has bearing in it to dampen vibrations, my bearings have totally gone and it just wobbles from side to side and spins extremely freely. The pulley is just behind a smaller pulley and is held on by 3 allen key bolts.

[Dutch24V 0]

Well, having done some further investigation it appears that the PAS pump is shagged. Just for confirmation its the pump with the large pulley down and directly in front of the crank pulley? It has a pipe running out under the radiator and then back under the engine - I presume that's the PAS pump?

 

Anyhow, If I turn it by hand, sometimes it spins freely, then others it sticks badly and makes a grating metal sound, and it's almost at the point of locking up for good I think.

 

Now calling VW for a price, but I bet it's expensive!? :(

...still, at least it's not the crank or big ends so can't complain...

 

Dutch

[Dutch24V 0]

Got a quote of 250 euro inc. VAT for the PAS pump.

 

He said it was the same as in a Polo? :? - that can't be right surely??

Going to call another VW dealer to check...

[Dutch24V 0]

This is the bugger:

 

PAS pump?

[edd 0]

Go GSF think they are around 140 something with a 40 refund on exchange. Not sure on situation with postage fees though!!

[Kevin Bacon 5]

Good news on the pump mate (well, it's cheaper than a new block!), it should be a ZF alloy one.

 

Did the steering not get progressively heavy prior to making this noise? My steering is mega heavy and my pump whines a lot, so I can expect this lovely rattling soon then.....but I've got a spare PAS pump anyway, so no biggy :-)

[Dutch24V 0]

Yeah, thank god. 8)

 

Not that I'm aware off, or at least I didn't notice and it didn't whine like I've heard VR ones do before!?

 

They look fairly straight forward to replace, but is there a drain hole or something for the fluid?

 

Dutch

[Dutch24V 0]

Err, having investigated further, I think the PAS pump is ok. :)

 

The belt was still turning the water pump pulley, which is now what I believe to be the problem. It wobbles severly and has about 2mm play in it when the belt is slack!?

 

I think this must be the same as your problem then Rich, which is even cheaper, but how do I get to it? It looks like I'll have to jack the front of the engine up about 4 cm to access properly? Is that possible?

 

See pic. (look at all that lovelly oil pouring out from the HG too :oops: )

 

 

 

Dutch

[Dutch24V 0]

Also, the wire you can see in the above pic. that runs under the airbox is chaffed down to the bare wire. I presume that's not good, but what is this wire for - the headlights?

 

Rich, I'm not sure what part you refer to earlier now as the water pump and it's pulley are the only 2 bits I can see on ETKA? I'm going to order a new pump and pulley anyhow as I presume the pulley shouldn't have any play in it (about 2mm in my case) when the belt tension is released?

 

The bloody fuse for my blower motor keeps blowing too, even when the motor is disconnected? :roll:

 

...and the reverse lights have both decided to blow and my alarm is acting a little funny - arming itself every now and then and not stopping when I disarm it. I've had to rip the wires off the siren for now!

I guess we buggered up some wiring when we did the heater matrix? I don't know, it's all too random and along with the water pump it's not been a good day for the C :(

 

Dutch

[Kevin Bacon 5]

Yeah you need to jack the engine up to get to the water pump, but slacken the bolts holding the pulley to the pump *before* you release the belt tension ;-)

 

Don't forget to undo the front engine mount before you jack it up or you'll just lift the car off the ground :-)

 

Yeah the wires under airbox are for the headlights, indicator, fogs etc and probably the outside temp sensor too. Put some foam on top of the loom to stop the airbox chaffing them. The airbox can also chaf through the carbon canister hoses. Quality Control is not one of Karmann's strong points.

 

Odd wiring gremlins there..... almost certainly something happended when you did the matrix. Since doing mine and also fitting the OBD2 stuff, I've lost power to the sunroof and courtesy light circuits. I hate wiring!

 

I'm afraid you're going to have to do some end-to-end wiring fault finding and that's a real ball ache.

[Dutch24V 0]

I've found a guide to doing the water pump and it doesn't seem too bad as it goes. Will undo the exhaust manifold along with the engine mounts though as I don't want that breaking too!

 

Yeah, bloody wiring. The wiring around the blower motor is all taped together with the alarm wiring, so guessing (hoping) it's something round that area. All the other wiring behind the dash was very tidy with no loose ends etc. so fingers crossed.

 

What's the worst that can happen if I drive the car and the water pump seizes? Obviously I'll keep an eye on the temp. and will stop if it starts rising too high, but more worried about the pulley actually coming off and doing some serious damage to the crank pully etc.??

 

Dutch

[dr_mat 0]

At least there's the secondary, electric water pump on the VR, but bear in mind that if the water is moving through the block very slowly, it may take a time before any signficantly hot water reaches the thermostat unit and the temp sensor (and your gauge!).

I'd be nervous about driving anywhere without a working water pump, given how much heat these things put out.

[Dutch24V 0]

Good point there dr_mat, and my secondary pumps bearings are also shagged so don't really trust the combination to drive the 130km's round trip to work tbh. :(

 

B*llix, guess I know what I'll be doing this weekend!

 

Dutch

[dr_mat 0]

I was thinking you might get away with it for 5 miles or so, but not 70! :)