Use of 5W-40 in a gas direct injection car prone to intake valve deposit

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May 27, 2002
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Would use of 5W-40 oil be a problem for cars with GDIT prone to intake valve deposits (IVD). No concern about warranty. Why could or couldn't 5W-40 be used in such applications? Would it really be better to use Dexos 1 Gen. 2.?
 
What kind of car/engine. I would put on catch can to keep all possible oil out of the intake and use Dexos 1 gen 2 in 5W30, changing at about 50 to 70% oil life.
Car specific info will come from those more knowledgeable than I on your specific car.

Rod
 
I haven't heard of a car call for 40 for decades. What weight does it say on the cap?
 
It's possible that it could increase the rate of build up. The efficiency of the PCV system along with engine tuning, design have a lot to do with it as well. IMO to alleviate your concerns look for a 5w40 with ACEA C3. The corresponding Euro approvals would be BMW LL04, Mercedes Benz 229.51, Porsche C40.

Does Dexos 1 Gen. 2 allow for a 40w?
 
If the car has EGR but no port injection then no change in oil weight or oil rating is going to help with valve deposits.

An oil catch can might make a marginal difference, but the Subaru WRX owners with direct injection haven't had good luck with them.

If the car doesn't have EGR, an oil catch can might be worth it.
 
Would use of 5W-40 oil be a problem for cars with GDIT prone to intake valve deposits (IVD). No concern about warranty. Why could or couldn't 5W-40 be used in such applications? Would it really be better to use Dexos 1 Gen. 2.?
I have built stock and high performance engines for 55 years, and have owned Fords, Chevy's and Dodges. and not one time have i used the type of motor oil that the factory recommends, Manufactures are in business to sell you cars, not to make yours last, the reason they recommend thin oils is to meet cafe standards for gas mileage, In my vehicles if it calls for 5w20 then i run 10w30 for 30,000 miles then i go to 0w40, I have put no less than 150,000 miles on an engine and never a problem, I put 250,000 on a Ram 1500 with MDS. which calls for 5w20 and i ran 0w40, and the MDS worked perfect, i tore the motor down to examine the cam, bearings, cylinder walls, pistons, valves, ect. everything looked really good, so do not try to sell me what the manual says, i know better, Thin oil does not have the HTHS to protect those bearings and camshaft and other related parts. And forget the oil pump excuse as well.
 
A lot of 5w40 are full saps and not formulated to be LSPI friendly. If you went out of your way to use mid or low saps offerings I'd expect you'd be just fine in most applications.
 
A lot of 5w40 are full saps and not formulated to be LSPI friendly. If you went out of your way to use mid or low saps offerings I'd expect you'd be just fine in most applications.
Stop worrying about saps or all the other crap, auto manufactures have been lying to you for years. I have been running shell Rotella 15w40 in a Chevy Tahoe for over a 100,000 miles and no emission problems ever, Cat Convertor still in excellent shape, passes smog test every time. All this worrying about ingredients in oil is pure BS.
 
Stop worrying about saps or all the other crap, auto manufactures have been lying to you for years. I have been running shell Rotella 15w40 in a Chevy Tahoe for over a 100,000 miles and no emission problems ever, Cat Convertor still in excellent shape, passes smog test every time. All this worrying about ingredients in oil is pure BS.
Always interesting to see a person's first post or so after joining.
 
Stop worrying about saps or all the other crap, auto manufactures have been lying to you for years. I have been running shell Rotella 15w40 in a Chevy Tahoe for over a 100,000 miles and no emission problems ever, Cat Convertor still in excellent shape, passes smog test every time. All this worrying about ingredients in oil is pure BS.
So you bought vehicle from people who are lying to you? That tells more about you than them.
 
Would use of 5W-40 oil be a problem for cars with GDIT prone to intake valve deposits (IVD). No concern about warranty. Why could or couldn't 5W-40 be used in such applications? Would it really be better to use Dexos 1 Gen. 2.?
WHat vehicle? WHat oil? Google might help you a bit.
 
I wouldn’t worry about intake deposits unless you’re driving the early GDI cars with the known issues like the Audi A4s, Hyundai Velosters and GM cars with the Ecotec 1.6l engines. I think the new cars have little to no problems in this regard especially if you give them the Italian tune up every now and then. Worse case scenario, you pull the intake and clean the valves while they’re hot and the deposits come off. I’ve done so on my Ford 2.0L turbo car. Didn’t notice any difference without the deposits. Car ran the same. My opinion is that there’s a bunch of fear mongering online about the issue.
 
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