Oil

[TsiRacer93]

ok, my cars got 100,000 miles on it, whats good oil to use. synthetic??? or regular??
gene

 

[candela]

cant ever go wrong with synthetic... Some say that it makes there car burn or leak when they switch to synthetic, but thats not the oil's fault. If you have a probalem with your car it should be fixed. IMO, everone should use synthetic if they care about there cars.

 

[MGTurbo]

My car has 93k on it now, and i use Mobil One 15w 50. The thicker viscosity at higher temperatures means there is less chance of it being burnt and going past the rings/bores.

It also offers good protection for the turbo being fully synthetic. Thats what i would use.


Gareth.

 

[doug]

Originally posted by MGTurbo
The thicker viscosity at higher temperatures means there is less chance of it being burnt and going past the rings/bores.
It also offers good protection for the turbo being fully synthetic.

I have no scientific proof of those two things, but that's the way I feel too-- although I still get about the same amount of blowby in my catch can. I've started using Amsoil 10W-40.

 

[MGTurbo]

Turbo cars suffer from blow-by quite badly when they have hit a certain mileage in my experience. 100k does seem to be that time but all depends how the car has been driven and treated in the past.

I had a Rover once (2.0litre DOHC 16v Turbo) that suffered from it very bad! The intercooler would fill with oil, and contaminate the throttle body. This then got into the MAP sensor and caused a misfire making the car undrivable. It had covered 172,000 miles though but ran great otherwise, changing the breather system to ATMO/catch tank helps reduce the pressure on the rings greatly which in itself will reduce blow-by.

Roughly how much oil are you collecting in your catch tank? My Rover would chuck out half a litre in less than 500 miles, it was quite bad!

Not sure what sort of breather system the DSM's comes with as O.E but suspect it would would be PCV for emisson regualtions (it's law over here), worth checking the air inlet hoses for signs of oil and also the intercooler, some oil is normal but excess could indicate either blocked breathers or excess bore wear.

Monitor oil consumption too, a quart every 1000 miles or so is pretty good for a high mileage car.

IMO, for example,a 5w 30 weight oil or similar is too light for a high mileage car, but if you've been using it in the past and oil consumption hasn't gone up, stick with it.

Gareth

 

[doug]

Originally posted by MGTurbo
Roughly how much oil are you collecting in your catch tank?

Well, certainly not half a liter, but enough to make me glad I DO have a catch can. I have the $3 catch can mod, which is just a cheap plastic fuel filter placed in-line with the breather hose. I'd say no more than half an ounce every month or so. A little does still get past the filter, though, and is continuing to contaminate the intercooler and piping.

 

[MGTurbo]

So essentially the breather system is till the same except for a small filter trap in the line? What are the regulations regarding open air brether systems in the US? It's not strictly legal to fit such a system to cars over here, they would fail the MOT, but if your careful there is nothing stopping you..

If possible, a full catch tank/breather system is an advantage on highly tuned turbocharged cars. I rigged up a cheap system, using an small expansion tank as my collector, on the top were the cap used to fit i attached a crankcase breather filter. It worked superbly. Open air breathers often make a stink, my tuned Austin Mini would reek of oil, i never had a tank on that one. The Rover did and i never smelt fumes once.

My friends Eclipse has problems with oil sitting in his intercooler, he often takes it out to clean it and can pour out a quantity of oil. In his case though it's not a worn engine, it's been rebuilt recently and doesn't burn any oil (i didn't notice any when i was having a race with him).
He does however have an old turbo fitted to it, i suspect its the seals on the inlet side causing oil to seep past into the intercooler. It's slow to spin as well, i reckon he needs a new turbo...


Gareth

 

[doug]

On these engines, some oil blowby is normal. Some people do use an open breather filter-- I might do that one day too. No, it's not smog-legal, but here in Florida, there's no emissions testing. I probably wouldn't do it if I were still living in California, the smog-nazi state.

The catch can mod I did is described here.

 

[MGTurbo]

Is that the only breather system the engine has? On my car, it has two systems. At idle a one-way valve on the inlet manifold is open to pull air out of an oil seperator/breather mounted on the sump face. As soon as vacuum decrease/boost pressure starts, the valve shuts and chucks out all fumes into the air intake. Someone mentioned to me that oil on the turbo intake fins could cause it to be unbalanced, a good point! Just imagine the fan in your office or house, with time a build up of dirt forms around the edge, making it noiser and slower. Just an observation but still a good point that could apply to the car!

The mod that you mentioned and i've now seen for myself looks like a cheap and effective way to prevent oil contamination of the intake system, and should work for most, especially the legal side. Just looks a bit odd having a fuel filter coming from the cam cover!

Might try it myself to see how much oil it's chucking out. I do have some oil film on the intake hoses but nothing serious. It's a split system now anyway, a hose still goes to the air inlet (one-way valve now removed), but at idle, fumes will be vented to atmosphere as the pull from the intake won't be sufficent. As soon as the car is under load it will pull through the air inlet just after the air filter.

A picture of the inlet side can be seen here:http://members.lycos.co.uk/mgmaestro/hpbimg/filtermg1.jpg


Gareth

 

[doug]

Originally posted by MGTurbo
At idle a one-way valve on the inlet manifold is open to pull air out of an oil seperator/breather mounted on the sump face. As soon as vacuum decrease/boost pressure starts, the valve shuts and chucks out all fumes into the air intake.

Sounds like what is here called a Positive Crankcase Ventilation (PCV) valve. I'm still a newbie when it comes to engines, though, so I don't know for sure. But yeah, these engines have one of those, too.

 

[turboholic]

Originally posted by jdoug


I have the $3 catch can mod, which is just a cheap plastic fuel filter placed in-line with the breather hose.

-I did use that set up b4, but once the filter material is wetted with oil, the vacumn still suck the oil through, I now use a catch can that made from a baby food jar, it works great.