Club G40 Forum

Technical => Engine and Transmission => Topic started by: Tony100 on October 28, 2009, 02:55:13 AM

Title: Problems With a Mates G40
Post by: Tony100 on October 28, 2009, 02:55:13 AM
Noooooooo its not mine this time!!! thank god!!! 

my mates bought a standad g40 had it for bout 2 years naw........... the only mods are an air filter and a 65mm puley

For the last 2 years its seems to be spitting out oil when he gives it some welly!

He seems to get oil on his drivers side chassis leg? naw theres not many things it can come out of

Am i right in thinking its coming out of his dipstick???

What would cause it to spit out oil on the drvers side leg??
Title: Re: Problems With a Mates G40
Post by: PeteG40 on October 28, 2009, 07:44:30 AM
on the chassis leg it could be the charger pulley seal, crank pulley seal, cam pulley seal or dipstick -  a number of things to check. 

Wipe it down properly then check again.
Title: Re: Problems With a Mates G40
Post by: G40supercharged on October 28, 2009, 08:54:37 AM
The problem is the breather system is blocked up. This causes the crankcase to pressurise and forces oil out of the dipstick tube, particularly when on boost. You need to clean out the breather pod (metal dome at back of block) plus black plastic valve thing attached to this. It's possible it may have damaged various oil seals but I would sort the breather and then see if the leaks go away. I got my first G40 in 1999 for about half the book price because it had this problem; cost 15 quid for a new breather valve and has been fine ever since. 
Title: Re: Problems With a Mates G40
Post by: PeteG40 on October 28, 2009, 08:59:02 AM
it COULD be the breather.. but i've rebuilt and engine with a clear breather but a disintegrating crank end plate gasket. 

Yes the breather can cause seals to go, but its not the only cause.  Some seals are nearly 20 years old now!
Title: Re: Problems With a Mates G40
Post by: Tony100 on October 28, 2009, 02:20:11 PM
Ye thats a good idea?

so whats best for him to clean/replace??????????


Clean the breather pod?? which requires taking it off? which means taking the inlet manifold off?
Title: Re: Problems With a Mates G40
Post by: vwmk3jon on October 28, 2009, 03:03:01 PM
Not accessible from underneath?
Title: Re: Problems With a Mates G40
Post by: Tony100 on October 28, 2009, 04:16:37 PM
Ive just taken the inlet off his car naw!! im assuming you guys are on bout the round thing the the charger breather comes from?? ( goes through the rocker cover onto the throttle bodie and the tee's off down on to this vavle??

This thing just spins when u try and budge it?? how do you take it off?? and am i taking the right thing off?
Title: Re: Problems With a Mates G40
Post by: Tony100 on October 28, 2009, 04:34:49 PM
(http://i6.photobucket.com/albums/y243/rochey88/100_2392.jpg)

(http://i6.photobucket.com/albums/y243/rochey88/100_2391.jpg)

This the valve you on aBOUT?? how do u test if its shagged?

which is attached to this??
(http://i6.photobucket.com/albums/y243/rochey88/100_2393.jpg)

What do  i do naw??
Title: Re: Problems With a Mates G40
Post by: Tony100 on October 28, 2009, 05:33:45 PM
how do i take the pod thing off the block?
Title: Re: Problems With a Mates G40
Post by: hayesey on October 28, 2009, 08:11:34 PM
it's just a press fit, need to prise it off with a flat screwdriver, just be careful not to damage it.  People normally bin the plastic one way valve and run a 1" bore pipe from the breather pod to a catch tank.
Title: Re: Problems With a Mates G40
Post by: Tony100 on October 28, 2009, 08:16:31 PM
Is it wise to run a catch tank some say its bad for the charger??

just need to run a pipe from the (pod) shaped metal thing on the block to a catch tank then get a charger blanking plate??
Title: Re: Problems With a Mates G40
Post by: G40supercharged on October 28, 2009, 11:48:35 PM
You should be able to blow through the valve thing; it flows more air one way than the other. If it's blocked you could try cleaning it with carb cleaner or similar. I've always just bought a new one. 
Title: Re: Problems With a Mates G40
Post by: hayesey on October 29, 2009, 10:01:35 AM
QuoteIs it wise to run a catch tank some say its bad for the charger??

you'll have to make your own mind up on that.  You'll prob find just as many people say it's bad as say it's better.  Personally I think it's better to use a catch tank and then spray the charger every 1k miles with a small amount of ptfe lube.  Where people seem to go wrong is either using the wrong type of PTFE spray or putting waaaaay too much of it in which just clogs the charger.  If done properly I think it's much better than lubricating the charger with the horrible crap that comes out of the oil breather.
Title: Re: Problems With a Mates G40
Post by: Tony100 on October 29, 2009, 03:32:30 PM
Whats the correct PTFE spray to buy?? and how much do you spray it?? at wot revs??
Title: Re: Problems With a Mates G40
Post by: hayesey on October 29, 2009, 04:39:12 PM
http://www.polog40.co.uk/merchandise.php

spray every 1k miles approx.  Just give it a couple of short sprays, rpm doesn't really matter, perhaps 1500, 2000... it's not rocket science, just don't unload half a can in there at once as some people seem to do!
Title: Re: Problems With a Mates G40
Post by: grayg40 on October 30, 2009, 01:01:42 AM
this was what mine was doing about a year ago, if its not the breather possibly pistons or rings checck comp.
Title: Re: Problems With a Mates G40
Post by: Tony100 on October 30, 2009, 04:05:44 AM
Can you take the rings out without taking the head off ??? ??


How much are rings thease days???
Title: Re: Problems With a Mates G40
Post by: Tony100 on November 09, 2009, 03:27:08 PM
how can you tell if its blocked ?? hes bought a new one and its still doin the same thing?? done a compression test and they are all round 110psi??
Title: Re: Problems With a Mates G40
Post by: hardchargin40 on November 12, 2009, 02:15:16 PM
Have you taken the breather pod off the back of the block and checked that the gauze is not clogged?

Have you got more oil than normal in your inlet system... i.e. charger seals weeping perhaps?

Piston rings would make it smoke more ( i.e. blue smoke) out of the exhaust i would have though as opposed to just on you chassis leg.

Is your throttle body bypass valve venting to air (the oil on your chassis leg being from that then) or returning to the charger?
Title: Re: Problems With a Mates G40
Post by: Dirty Slag on November 12, 2009, 02:23:55 PM
You cannot remove the pistons out the bottom!
Its impossible!
To check the rings the heads got to come off but this shouldnt take you anymore than about 40 mins!
It sounds to me like the rings are shagged or a pistons melted especially as your telling me its got a smaller pulley,airfilter and no other mods!
So stands a chance its run lean and cooked something (See the melted piston thread)
Title: Re: Problems With a Mates G40
Post by: Dirty Slag on November 13, 2009, 12:23:48 PM
Ok how do you get them past the crank?
And then how do you put them back in this i'd really like to see!
Title: Re: Problems With a Mates G40
Post by: hardchargin40 on November 13, 2009, 02:39:00 PM
I remember Mark Hunter doing this in a petrol station car park to replace a melted piston on his T40 (probably the UKs first Turbo'd G) :o :D


I doubt knackered rings will make it overpressurise and only come out of the dipstick, especially without seeing any kind of smoke out of the exhaust.  Performance will also be down.

Melted piston, you'd get a hell of alot more than oil on the chassis leg from a dipstick.

Does sound like the breather is blocked.  It should be less revvy aswell, more lethargic.  Also, Tony100 mentioned only mods being airfilter and pulley... i hope there is a 65mm chip aswell?

Tony100, has you mate cleaned it yet?
Title: Re: Problems With a Mates G40
Post by: Tony100 on November 15, 2009, 06:08:08 PM
Quote from: hardchargin40 on November 12, 2009, 02:15:16 PM
Have you taken the breather pod off the back of the block and checked that the gauze is not clogged?

Have you got more oil than normal in your inlet system... i.e. charger seals weeping perhaps?

Piston rings would make it smoke more ( i.e. blue smoke) out of the exhaust i would have though as opposed to just on you chassis leg.

Is your throttle body bypass valve venting to air (the oil on your chassis leg being from that then) or returning to the charger?

I havent taken the pod off the back of the casing cause it hard to move how to i take it off??

whats the guaze??????


Whats the throttle bypass vavle??
Title: Re: Problems With a Mates G40
Post by: swiftg40 on November 16, 2009, 11:59:54 PM
where the pod meets the crankcase you need to tap a screwdriver or a fine Chisel or something like that to separate them its a tight push fit.
(DO THIS GENTLY) as its only made of thin metal then clean it out with petrol and if its not blocked...refit as it was removed.
Title: Re: Problems With a Mates G40
Post by: Tony100 on November 17, 2009, 12:35:28 AM
So im assuming it will come out tight and go back in tight!!! shall i look at the oil pick up by taking the sum off?