Menu toggle

HG - Slightly Modded Turbo

scam75

scam75

Well-known member
Afternoon all

I suspect my HG is needing replaced. Have a water leak that I can see no sign of so the head will have to come off. Put a standard one on 60k ago but suspect when my wastegate diaphragm let go the 27 psi of boost I got up to may have hastened the demise of my HG! Mods are in sig below. Boost peaks at 21 psi in 5th dropping to 18psi due to MBC. Should I go with Victor Reinz again or upgrade to cometic or widefire??

Cheers

Stuart
 
Meant to say symptoms are water loss with no trace, tiny bit lumpy at tickover, oil pressure seems slightly down and yesterday started up on 3 cylinders for a few seconds before kicked on to 4. Also seems very pressurised, if I park up the night before, next morning when I top up water, still getting a fair bit of pressure release on opening header tank.

Also what are thoughts on using it before I do the job, cause more damage?

I'm pretty convinced water is getting into a cylinder.

Cheers

Stuart
 
hi stuart don’t use it mate,.. i had this and split my cylinder right through when water got in, cost me £8000

where abouts are you in the world
 
Take the spark plugs out in the morning, and then turn the engine over. When I did this years ago with my TR7 a water jet hit the garage roof. If a cylinder does have water in it, one plug may have been steam cleaned too. There's also a danger of hydro locking and bending a conrod. I think sniffers can check for carbon monoxide in the coolant also.
 
Thanks lads. Off the road it is. I will pull the plugs tomorrow for a look when I get a chance.

I'm near Glasgow Airport Dan if you fancy a long drive!!

Cheers

Stuart
 
hi Stuart,…good that your taking it off road till you fix it.

Bummer your so far,…was gonna say you could borrow my co2 tester . i bought x3 small kits from ebay for around £14 ? abd they were load of crap! they all came up negative , so i after my water pump pipe burst on a spirited drive , i decided to spend a bit more on a professional co2 sniffer kit and low and behold came up possative - co2 in my water , so if fb came the head and i’m suspecting a little scratch as i have the full stainless custom cometic gasket so as said above the surface is like a mirror so can be a pig to seal

think my kit es around £85 and unlike the cheap ones , you hand pump the air into the liquid from the header bottle whilst car is running

endascope would be good idea down the spark plug hole after a drive ?

Daniel
 
Update this morning. Plugs out, 1 and 2 swimming in oil (in spark plug wells), 3 and 4 much cleaner but all show evidence of oil burn deposits. The oil in plug well 1 has actually made its way up and onto the top of the head. 3 is the cleanest but not sure any evidence of a jet washing. Thoughts?

Cheers

Stuart
 
Ok so this issue seems to be a cam box gasket leak and not related to the water loss issue. Evidence of a cam box gasket leak around outside of cam box near 1 and 2. Electrodes on 1 and 2 have got some oil on them though, 3 and 4 cleaner but as said all plugs look to have some burnt oily deposits.
 
If there's no water in the cylinders, and a sniffer doesn't show a combustion leak into the expansion tank. I'd warm the car up somewhere dark, and using a torch look for a steam leak. Could be the rad, water pump or a hose.
 
Thanks Blade. So far I can't see evidence of an external water leak. Can't see evidence of oil in water or vice versa. Definitely using water though and water system seems over-pressurised, as said earlier still lot of pressure in expansion tank next morning after using car. Also we now know cam box gasket and seals are gubbed!
 
I lost water to the min mark all the time would never go lower than that, was a crack in the bottom of the expansion tank
 
My expansion tank cracked at the top, just above where the two bits join, below the min mark. Had it plastic welded. At 32 years old it may have been natural wastage but I think the over pressurisation has sent it over the edge. The repair has held firm but still losing water. About half a litre per 15 miles. Still stumped.
 
do a CO2 test in the header tank whilst engine running,…but get a proper one not cheap under £20 kit.

only way your pipes will pressurise is if the combustion gasses are escaping into the water jacket through gasket failure or crack in head or cylinders ect

also put a bottle on the engine bay with the overflow pipe from the header tank in the bottle , i used a fairy liquid bottle…. then go fir a drive under boost but not too heavy footed,… then let car cool after 30 mins driving abd take a look in the bottle. if water in there you should do the above co2 test and can also think about checking the preasure of the header cap to see if the spring releases at thecorrect psi but more than likely head gasket or crack but hopefuly not a crack.


 
Thanks Dan. I suspect the HG as you say. It's booked into my mates garage on Monday for tests. Sniffer test and boroscope etc. I'll report back findings.
 
Worth putting a bottle on the end of the overflow pipe from the filler neck you can then see if the water is coming out that way - Could be a weak cap but you had other signs of high pressure. Alternative places to lose water are many - the metal pipe above the exhaust manifolds is a good one - can go in pin pricks and spray onto exhaust and be almost invisible, Pin pricks in rad can also be tricky to spot. A leak would seem to counteract the pressure in the morning though, unless in the heating circuit maybe - but usually leaks in that area can be smelt inside - strange one!


 
Yeah Tony, agree on all that. I think the excess pressure here is the giveaway. A weak expansion cap would reduce pressure. I replaced the cap about 10 years ago IIRC, was weak when I bought the car. My oil pressure is also slightly down on normal but not massively. For me it's all pointing to a water leak into the combustion chambers. Hopefully the HG, although if it's block or head then so be it, just need to suck it up. Be a shame to lose the matching number block but worse things happen at sea!! As previously stated I whacked in excess of 27 PSI boost through the engine when the WG diaphragm let go, admittedly not for very long though as my eyes are never far from the boost gauge! That was sorted a couple of years ago but it makes sense it has fast forwarded the demise of the Victor Reinz HG, which has seen about 60k miles now. Good news is the engine has not overheated at any point, so with a bit of luck it's a straight-forward HG change over with a light head skim.

Any external water leak would reduce the pressure in the system. I have the opposite. See what transpires.

Stuart
 
Evening all. Left the car today with my indy Porsche mate. Did boroscope amongst other things. Not spoke in detail yet but he texted to say "heavy water ingress cylinder 4, severe bore markings and oil ingress cylinder 2". He is calling me in morning for more in depth chat.

I'm reading this as the block is fucked and will need sleeved or replaced. What is your thoughts on this early diagnosis?

Cheers

Stuart
 
Sleeve it. See my thread, speak to Alistair at AMAC Engineering in Northallerton. A mate in Lincolnshire is getting his 3l Turbo block overbored and sleeved by them too.


Happy to shout you a coffee if you’re passing.
 
Cheers Dave. Just send the block to Alastair then and it would be returned ready for pistons and building back together?

I'll come for a coffee when the car is fixed!

Stuart
 
You must log in or register to reply here.

Posts made and opinions expressed are those of the individual forum members

Use of the Forum is subject to the Terms and Conditions

Disclaimer

The opinions expressed on this site are not necessarily those of the Club, who shall have no liability in respect of them or the accuracy of the content. The Club assumes no responsibility for any effects arising from errors or omissions.

Porsche Club Great Britain gives no warranties, guarantees or assurances and makes no representations or recommendations regarding any goods or services advertised on this site. It is the responsibility of visitors to satisfy themselves that goods and/or services supplied by any advertiser are bona fide and in no instance can the Porsche Club Great Britain be held responsible.

When responding to advertisements please ensure that you satisfy yourself of any applicable call charges on numbers not prefixed by usual "landline" STD Codes. Information can be obtained from the operator or the white pages. Before giving out ANY information regarding cars, or any other items for sale, please satisfy yourself that any potential purchaser is bona fide.

Directors of the Board of Porsche Club GB, Club Office Staff, Register Secretaries and Regional Organisers are often requested by Club members to provide information on matters connected with their cars and other matters referred to in the Club Rules. Such information, advice and assistance provided by such persons is given in good faith and is based on the personal experience and knowledge of the individual concerned.

Neither Porsche Club GB, nor any of the aforementioned, shall be under any liability in respect of any such information, advice or assistance given to members. Members are advised to consult qualified specialists for information, advice and assistance on matters connected with their cars at all times.

Porsche
Lockton
Pirelli
Officially approved
Oracle Finance
WEX Esso
Collecting Cars
Archant Dialogue
Back
Top