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-   -   GTS Has Stopped Burning Oil (https://rennlist.com/forums/928-forum/560900-gts-has-stopped-burning-oil.html)

OJ GTS 04-08-2010 11:42 AM

GTS Has Stopped Burning Oil
 
Hello all

Last year, covering when I was commuting about 55 miles at high speed each way to work, my GTS was using about a litre (near enough a quart for the non-metric) every 500 miles. I covered 5 or 6k doing that, not really concerned as the GTS has a reputation for using oil and usage has been consistent since Dad bought it in 1998.

Referring to the previous owner (Dad), he'd topped it up with a litre about every month, when he was commuting into London, on about 20 miles a day in heavy traffic, so slightly less usage mile for mile.

Recently, it's almost completely stopped using oil (and no it's not empty ;)). I've covered about 1000 miles over the last few weeks and it's barely moved off the top notch of the dipstick.

Is it broken? :D

Oil brand hasn't changed (and I'm not starting that one), the only thing that's different is the weather (car was last used in the summer and it's now still cool here in the UK), and the HVAC has been refurbished having never worked properly with the 'main valve' being replaced (forgive me for not knowing its proper name).

The car went through a period where I was starting to get worried, using about a litre of oil every 300 miles, but I put it down to a particularly hot week where I spent a lot of time booting it about on the motorway driving to circuits and sponsors. I got someone to drive behind me while I floored it, and they witnessed a puff of black/grey smoke on accel.

Theories so far at work (powertrain engineering) have been:

a) Broken Valve on HVAC was upsetting the crankcase breathing somehow

b) Old man drove it like... err... an old man (unlikely) and my heavy right foot has finally deglazed the bores/seated the rings/whatever

c) Worn out MAF (soon to be checked) is overfuelling on hot summer's days and causing bore wash, but in cold, dense winter air it's about right.

Any other suggestions, opinions on likely causes welcomed

pcar928fan 04-08-2010 12:10 PM

If the car is running well, just count yourself lucky. None of the things you describe should have any impact on how or why a GTS burns more oil than an S4. FOR SURE they burn more when you are running them hard! A track weekend will EASILY burn over a quart in a GTS.

SteveG 04-08-2010 02:27 PM

I vote for "b", with editing. I thought the GTS consumption was blowby, so I would think it might affect valves and be evidenced on the plugs. If so, there would still be evidence there. Otherwise I'd join James and just enjoy the circumstance.

OBehave 04-08-2010 03:06 PM

Maybe your out of oil.:icon107:

9two8 04-08-2010 03:18 PM


Originally Posted by OBehave (Post 7466549)
Maybe your out of oil.:icon107:

{QUOTE= .., it's almost completely stopped using oil (and no it's not empty ).
-----------------------

Ken
80 928 S
5 Speed

UK

OBehave 04-08-2010 03:33 PM


Originally Posted by 9two8 (Post 7466585)
{QUOTE= .., it's almost completely stopped using oil (and no it's not empty ).
-----------------------

Ken
80 928 S
5 Speed

UK

Yeah I know,guilty as charged.I thought I had that" Post first,Read later" thing under control.I will work harder to fix that.:cheers:

Leon Speed 04-08-2010 04:04 PM

High rpm's cause a lot of blow by. Drive it in an easy going manner, you can go a long way without having to add oil. It is that simple (well except for the part about driving it in an easy going manner ;)).

Charley B 04-08-2010 04:30 PM

Not the first time I have heard of a GTS using much less oil after mileage has accumulated between 50K and 100K miles. Mine improved appreciably between 50K and 60K but I was trying different oils and viscosities so I have no way of knowing where the results come from.

Tom. M 04-08-2010 04:58 PM

You must be measuring wrong because it's a known fact that all GTS' burn massive quantities of oil..I've not seen one that doesn't :icon501::icon107:


Waiting patiently for Chuck Z to chime in :evilgrin:

dprantl 04-08-2010 05:01 PM


Originally Posted by Tom. M (Post 7466883)
You must be measuring wrong because it's a known fact that all GTS' burn massive quantities of oil..I've not seen one that doesn't :icon501::icon107:


Waiting patiently for Chuck Z to chime in :evilgrin:

Of course... it even says so in the owner's manual :icon107::icon107:

Dan
'91 928GT S/C :eek: 475hp/460lb.ft

andy-gts 04-08-2010 05:05 PM

oil
 
could the oil be diluted with gas possibly?:icon107:

Charley B 04-08-2010 05:06 PM

Ye bastids! :grr:

AO 04-08-2010 05:11 PM


Originally Posted by OBehave (Post 7466636)
Yeah I know,guilty as charged.I thought I had that" Post first,Read later" thing under control.I will work harder to fix that.:cheers:

Thank god I'm not the only one with that affliction... :thumbup:

soontobered84 04-08-2010 05:30 PM

Mine uses virtually no oil ....201,000 on the odo.

Freaked me out intitally.

ROG100 04-08-2010 09:47 PM

Seen an improvement with mine after 120k.
The ProVent helps as well.
Roger


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