Why Do Engine's Use Oil?

[RAF_gti 0]

After owning my 1.9 for a good few months I've started to notice it using a wee bit of oil, especially after runs of 500 miles or so (I've done a few big journeys recently). The engine runs sweet as a nut IMO and was rebuilt by DES approx 7-8K ago. I was informed by the previous owner that he ran it on 10-40 semi but he wasn't sure of the brand. After running it myself for 900 miles and not using a drop I changed the oil to Total 10-40 semi and noticed it running just a little bit rougher than before, certainly what I would attribute to a change of oil. I have also had to top it up now fairly regularly but that as I said, may just be down to the very long journeys I have been putting it through.

 

Should I be un-duly concerned? Is there anything I can do to test the engine? Are there any particulary good oils which suit the XU engine?

 

Performance wise the engine seems fine, if lacking that final 'finesse' which it seemed to have before the change.

 

Steve

[Richie-Van-GTi 70 2 Cars]

if its only a small amount and it isnt smoking dont be too concerned, it will burn a bit through the intake breather system and the car is old so expect a bit of wear on the bores and rings, valves etc. Personally I always use millers XSS 10-40. Other oils seem to make it run that bit noisier.

[gti-si 0]

Compression test will check your rings and general conditon, but they usually do use abit of oil, shouldnt be noticing too much really though. I think oil brand will have little/no effect on performance, but perhaps make it a tad nosier. Have you checked thoroughly for leaks in the suspect areas? If it's not blowing smoke through the exhaust and you don't have any oil in your water or vice versa and/or mayo, i'd say you've not alot to worry about. Just have a look for leaks

 

i've been writing this for 20 minutes, think i got distracted and richie beat me to it haha, so what he says

Edited July 23, 2007 by gti-si

[Rob_the_Sparky 9]

Most likely to be worn valve stem seals or piston rings. Good idea to get someone to follow you and observe the exhaust for blue smoke.

 

If it is stem seal then it will suck in oil on the overrun and burn that in a lump when you put your foot down again. E.g. puff of smoke when you put your foot down after the overun.

 

Rob

[C_W 3 1 Cars]

If it was rebuilt only 7-8k ago (including piston rings and seals) then it might not be fully bedded in yet, and if the journies you've been doing are long ones (assuming motorway?), then it might be an idea to give it a good thrash through the gears after water and oil are up to temp.

[Anthony 1,000]

If it is stem seal then it will suck in oil on the overrun and burn that in a lump when you put your foot down again. E.g. puff of smoke when you put your foot down after the overun.

And if they're worn badly enough, it'll be smokey and/or smelly on idle as well

[snillet 1]

If it was rebuilt only 7-8k ago (including piston rings and seals) then it might not be fully bedded in yet, and if the journies you've been doing are long ones (assuming motorway?), then it might be an idea to give it a good thrash through the gears after water and oil are up to temp.

 

I would say the same, freshly rebuilt engines need a "bit" of trhasing around to get the pistonrings/liners to seal upp good together, whatever you do, do NOT treat it to "nice" cause that´ll cause the liners to be "glazed" if you´re unlucky and the engine will never really come to life again.

 

I have seen that on large diesels that dirves waterpumps where the owners thought "i do not need all that high-rev capacity right now, i´ll just run it on idle". The cylinder bores get glazed and the engine starts to run REALLY bad at low rpms and consume a sh-tload of oil. Is usually solved by revving good under load for a while.

[RAF_gti 0]

Thanks for the replies guys, I've had a closer inspection underneath and there is certainly evidence of oil leakage, albeit just a little...I hope! I will need to get her up on the ramps this weekend for a closer inspection, hopefully it won't be a major problem. Before I go off on a search button mission are there any very common oil leak points I should be aware of?

 

Steve

[gti-si 0]

Camshaft oil seals, the O-ring on the distributor and the rocker cover gasket. There's also the dipstick (where it connects to the block) and the sump area to check

[Guest SeanGTI]

well from my experiences on leaking oil. the problems areas are the O-Ring on the distributor, camshaft oil seals and occasionaly the rocker cover gasket. and for some reason on mine it always leaks from the sump gasket. after all the times i have replaced it.

[Henry Yorke 269 3 Cars]

As already mentioned, I use Millers XS-S 10/40 too. I have found this the best for oil pressure and stays golden in my engine the longest!

[Furiousd 0]

Thanks for the replies guys, I've had a closer inspection underneath and there is certainly evidence of oil leakage, albeit just a little...I hope! I will need to get her up on the ramps this weekend for a closer inspection, hopefully it won't be a major problem. Before I go off on a search button mission are there any very common oil leak points I should be aware of?

 

Steve

 

I had a crack in my oil filler pipe, so check this whilst your at it!

[Ahl 4]

When I replaced the stem seals on my old 1.9 and sorted out all of the oil leaks, it honestly didn't use any noticeable amount of oil at all.