4722 replies to this topic

[Nev]

I had an el-cheapo Eurocarparts VW copy pump leak on one of the trucks I work on after 15hrs running.

Jubilee clips can be shite Something like THESE are better if you can get them in the size you need.

I agree, I should buy a Mikalor set in that size as you can get 10mm spanner on them and torque them till your arm hurts !

Edited by Nev, 05 March 2013 - 08:53 PM.

[Nev]

Well, it has warmed up over here in Bristol, so I launched my lazy arse into high speed action in the garage this morning. In 1h 40m I managed to take the rear clam off and strip down the anciallaries (and check the cam timings) so I could inspect the water pump. It is indeed leaking as there are water/coolant witness marks on it. Now I just need to order a new water pump and cam belt and reverse the process next weekend. Hoorah.

Edited by Nev, 16 March 2013 - 11:28 AM.

[Nev]

New pump and belt ordered. Just £91 delivered from Evans Halshaw in Newport

Edited by Nev, 16 March 2013 - 12:46 PM.

[Nev]

Pump and belt went astray in the post (thieving posties!), so had to ring them up after 4 days to ask where it was. They were good as gold and sent a replacement immediately with no quibble, which arrived the next day.

I am also keen to check my boost pipes for suspected leaks. To do this I am making a bespoke bung to fit into the boost pipe that leads from the turbo. This will allow me to temporarily insert the bung into the 2" rubber boost pipe (with a jubilee clip to secure it) and then fit my air pressure line to it with a standard 1/4 " air line attachment. Then with my compressor I can blast air into the pipes and listen/feel where it is escaping. A simple tool, which I have to thank Dave Hardwick for suggesting. I had originally asked him to weld me one up out of metal, but he talked me out of it and I've just been down to B&Q to get the parts to make it, which came to a sum total of £ 2.49. Thanks Dave. There is a pic of it below (as the epoxy sets with help from a radiator in the house):



If anyone in .Org needs to borrow it they are welcome

Edited by Nev, 23 March 2013 - 02:14 PM.

[siztenboots]

thinking of making up the same with a tyre valve

[Dave H]

That should do the job Nev. Just a word of warning while you are doing this or a leakdown test, there is a chance that the air pressure can turn the engine over so keep clear of anything that can rotate and if its in gear handbrake on and chock the wheels!!!! Dave

[Nev]

Well, I've fitted the new water pump and cam belt on the car and turned the engine over with the starter motor (without plugs in) and all seems fine.

I then went on to use my new pressure test bung and there seems to be a leak in the system. Suprisingly all the pipes and joins seem fine, however a rather suspicious sound was coming from the intercooler. I have recorded a video here:

[media]http://www.youtube.com/watch?v=PP1BXv2k6eQ&feature=youtu.be[/media] .

Can someone with experience of doing this let me know if they think this sounds like boosted air escaping into the water matrix or perhaps to atmosphere? I did also put my hand over the IC water tank to see if positive pressure was escaping there (via the water pipes from the IC), but nothing was detectable and I saw no bubbles rising out of the coolant.

The video shows how 20 PSI is leaked out in aproox 15 seconds. The noise sounds as if it is coming from inside the unit (perhaps). I did run my hands up and down the sides that were accessable, but felt no air escaping. I also tried using a 1" flexi pipe to my ear (like a stethescope) to try and locate a specific leak but came up with nothing. However, only about 50% of the IC is actually accessable to do this test, so it is not conclusive.

Normally my compressor will build pressure to 120+ PSI, however whilst plumbed in to the car the max it could reach was approx 30 PSI, so clearly there is a leak somewhere.

Image of the bung on the start of the boost pipes system:

Edited by Nev, 23 March 2013 - 05:57 PM.

[Nev]

thinking of making up the same with a tyre valve

Easily done Steve, or feel welcome to use mine and just buy a 1/4 inch to schraeder valve adaptor to connect to it.

The plastic pipeing was a bit of plastic plumbing pipe from B&Q with a 2" O/D.

Cheers, Nev.

[Zoobeef]

Air will be getting out your exhaust valves and out the exhaust won't it? The noise you hear may just be the air rushing through the matrix

[Zoobeef]

A smoke test may be easier to see aswell

[Nev]

Thanks for the input Mark. Yes, it's hard to know how much I should expect leakage wise out of the valves (and maybe the inlet manifold which only has a stupid paper gasket where it mates to the head). How could I perform a smoke test? I've not done one before, do I buy a reactive binary substance and drop it into the boost pipe and then pressure it up ?

[Zoobeef]

Blocking up your exhaust tailpipes may get the pressure up a bit more. Ive never done one but using a smoke machine then pressuring or some sort of smoke tablet. Just means the leak should be visible as well as make a noise

[siztenboots]

if the exhaust valve is open the inlet valve should be closed , for each pair of cylinders. Can you check pressure on the chargecooler system

[Zoobeef]

There will be valve overlap to aid scavenging as on the exhaust stroke the inlet opens before the exhaust shuts. If you have all the pistons at the centre of the bore it should get rid of that but the air may turn the engine as mentioned above. A compression test will check your valves and rings are sealing.

[siztenboots]

yep, Nev has some wild cams in his.

[Nev]

Hmmm, food for thought. I have also had a chat with Dave Hardwick and have a couple of more tests. Will have another bash tomorrow and if I can't find a leak will just stick the clam back on and drive the bloody thing. Maybe the noise I am hearing is quite normal as the charge passes over the intricacies of the matrix, so perhaps I am making a mountain out of a molehill !

[steveboyslim]

Remove the boost pipe from the inlet manifold and plug that end and re-test, it will not be possible to test the manifold as the throttle butterfly does not seal good enough and unless you have the engine in the correct position (you can turn each cam follower with your fingers) the valves will be open on at least one cylinder and as all four cylinders are linked via the inlet plenium you will have no chance of determing if you have a boost leak. The cams in Nev's engine are very good, I have them in two similar specification engines which give a genuine 620+ bhp (different turbo, inlet manifold etc), with the correct mapping (and in some cases correct ecu) and injectors give good idle, emissions and drive like 'shopping cars'. Steve

[cnrandall]

Are they hydraulic profiles Steve?

[Nev]

Thanks for the suggestions guys. Chris, the cams + lifters are mechanical profile. I am now of the opinon that the IC is not leaking. Whaver pressure is leaking out is likely going through the engine and the noise is probably the air flowing over the matrix. Anyway, the leak (if there is one) is pretty minimal and the supply of air from the turbo is massive in comparison, so would be of little consequence. However, after starting up the engine this morning I once again have oil coming out of the exhaust (though only once the car warms up and the oil thins). When I did my boost test yesterday, I found a good deal of oil in the boost pipe leading from the turbo to IC, so it is fairly likely the oil seals/bearings on the turbo have failed IMO. An expensive new CHRA will probably be required if this is the case, though I am worried this problem may repeat itself. However, as prevention, I have now installed a 1 mm oil pressure restrictor to the feed to the turbo, which hopefully would protect the new CHRA. Any further ideas? Or shall I just bite the bullet and buy a new CHRA ?! At a guess, I would have thought that once the oil seal/bearing on the turbo has allowed oil to escape past it, it would not be 'irreversably' damaged. By having added the oil pressure restrictor to in the inlet oil to it, I would have expected it to resolve the problem. However, this appears not to be the case...

Edited by Nev, 24 March 2013 - 10:22 AM.

[siztenboots]

iirc the z20let and z20leh both have a common oil pump , I have not read an informed opinion that at high rpm this causing a problem, but if putting in a oil restrictor to the turbo feed has no downsides then I will remove factory fit part. But can localized oil temperatures be a factor here.