Looking to Reduce Oil Consumption in a Turbo Engine....

[Idrinkmotoroil]

I've been running my Dodge SRT4 for over 2 years now. It runs a turbocharged 2.4 L engine, max boost is 19 psi, and it runs pig rich with fuel at WOT. For the most part I run Mobil1 10w30. The engine used very little oil the first year I had it, usually 1/4 quart between oil changes. I then installed a Mopar stage 2 upgrade and since then oil consumption has been worse, about 1 quart between oil changes. The stage two kit increased max boost to 19 psi from 14 psi, and added a ton of fuel making the air fuel ratios pig rich. I also had the same consumption levels running Redline 10w30. My OCI's are 3000 miles in order to keep the warranty guys happy.

For some reason oil consumption just irritates me, I prefer to have an engine maintain oil levels between changes if it's possible. Can anyone recommend an oil that might have less consumption ?. I'd prefer to stay in the 30 weight range if I can, since this engine uses a balance shaft system and the bottom end has absolutely no windage protection. A 40 weight may make it sluggish.

I'm not sure what's made the consumption rise, I don't drive it very hard, and the engine seems mechanically sound. I'm wondering if the extra fuel is doing something to make the oil more volatile. UOA's I've had done show wear numbers as being very low, with no fuel or water in the oil, & it runs quite well on a dyno - 260 whp and 280 ft lbs to the front wheels. Never any blue smoke out the tail pipe eithre. If I knew where the oil was going I might be less concerned, but I am wondering if the piston rings are seizing up with varnish or something like that.

Any suggestions on an oil that might work better in this setup would be appreciated, thanks very much.

 

[Last_Z]

The thickest 30W oil I know is GC. It's a good oil and it's 12.2cSt....I think you should give it a try! Also, why don't you spend a bit of dough and get that rich condition fixed by re-tuning your PCM? You'll make more power and keep the engine happier. Also, you are making mad power with that 2.4L....it has got to burn some oil with that much boost. What has your fuel % been in past UOAs? I think some oil burning is going to happen in this car. Just think of the heat created inside the cylinders.....it will burn some of the oil coating them.

 

[AndyH]

Since you live in Canada, another choice in a thicker 30-weight would be ESSO XD-3 Extra 0W-30, it is 12.1 cSt @ 100°C. Cheaper than GC as well, if I'm not mistaken.

 

[CBODY67]

I concur on getting the computer retuned on a chassis dyno under load. I've read of Mopar Perf fuel maps being very rich under high boost, but it should not be as lean at that type of operation as a non-turbo engine would be. Consider the "rich" condition to be a built-in cooling device of sorts, but it's obvious that it could be leaned out a little (as some magazine articles have noted). Perhaps the guys at Forward Motion might have some ideas on fine tuning the system?

In a turbo motor, considering that you do not have the orig OEM setup--if that really matters as such, oil "consumption" can also happen at the turbo seals. That was a problem with the first Buick Turbo 3.8L V-6s (in Monte Carlos is where I saw it, in the first years of production)--the seal would fail on the exhaust side and slowly empty the oil pan.

I also hope that you're letting the turbo spool up and down each time you start and stop the engine? I noted that in a Ford Turbo T-bird service doc (back then). In a cold start, let the engine idle so that the turbo has oil pressure (good) before driving the vehicle and the turbo spinning faster and building boost. Similarly, it advised to let the engine idle for about a minute or so before shutdown, so the turbo could spool down before the oil pressure went away. Things I hadn't thought about at the time, but they made sense to me.

It's possible that a different oil can decrease your consumption issues. Have to try it and see. Plus, if you are "using" the added capabilities, that can have some affect too, with all due respect. Just like the "ring flutter" issues on some earlier LS1 architecture Corvette V-8s would only surface during low-load high-rpm conditions.

Any factory-based/supplied "increased performance" part will have certain built-in safeguards. Probably moreso than a similar aftermarket part.

Going to a __x40 oil from a x30 oil might make a little difference in power and response, but not as much as going to a x50 oil. But if the x40 oil helps with the consumption, then the small additional power absorption might be a decent compromise on the street.

Have you contacted the Mopar Performance Tech Line on this issue? They might not recommend a particular oil brand as such, but perhaps they can lend some guidance on the issue.

Just some thoughts,
CBODY67

 

[BrianWC]

AF ratio shouldn't affect oil consumption. I've owned two turbocharged Saabs and both of them run rich at full boost. It's a safety measure to prevent detonation. My latest saab is known for fuel dilution and I really don't loose any oil, still. With regard to letting the turbo spool down, older cars which had oil cooled-only turbos were very susceptable to coking but the more recent ones w/ water cooling have made this ALMOST a thing of the past. Common sense rules still apply on starup just like a normal car.

Have you thought about inspecting the PCV system? This is the killer on later saabs and it's important to check on all boosted cars to avoid issues.

If you've got leaking seals, I would expect it to be more obvious that you are loosing oil. If a seal is leaking on the intake side, you should have lots of nice gunked up stuff on the way to and in the combustion chamber. If it's going directly out of the exhaust side, I would think you'd already have something like a failed catalytic converter.

Might I suggest (and I hate to sound simplistic) but...auto-rx?

 

[forcedtalon]

Yea I would try running the GC 0/30. Like the other guy said may want to run 2 oz of auto rx at every oil change to keep the ring packs clean of carbon.

 

[JohnBrowning]

I would try one of the following Redline 10W40 or Amsoil S3000 5W30 or Delvac-1 5W40 not TSUV 5W40. The fuel is dilluting(sp) the oil wich lowers the flash point. Eventally the fuel is burnt off and the flash point comes back up. If the Redline 10W40 does not do it though I would think nothing would!Redline has the highest flash point and HTHS of the bunch.

 

[Idrinkmotoroil]

thanks for all of the great replies. This car runs rich in stock form and in the Mopar staged upgrades for safety reasons, it extremely rich though, between 9-10 :1 approx. air fuel ratio range.

There is a lot of power to be gained by leaning out the air fuel mixture, a lot of guys have done it, but I don't want to get into that for reliability and warranty concerns. My UOA's never detected any fuel in the oil samples.

I think I may start with a thicker 30 weight and take it from there and see if things improve. I'd love to run Redline 10w-40 oil but Dodge restricts us to short oil change intervals for warranty coverage and Redline is too expensive to dump out on early OCI's. I run Redline 10w-40 whenever I go road racing on the track and it works unbelievably well. It protects really well and is even great for fuel economy, so I've got to think it has really good frictional properties. But I just can't afford to run it for short daily driven OCI's.

I wish I could buy Auto-rx in a local store , I'm not fond of purchasing fluids by mail delivery. I'll try to get around to it one day though as it sounds like a great product.

Thanks for all of the great info, I may start with Castrol GC or Esso 0w30 and work my way upwards if things don't improve.

 

[Islandvic]

Valvoline MaxLife Synthetic 10-30

 

[JAG]

I'd put an oil-catch can on that engine.

 

[BrianWC]

Perhaps try a quart of Redline w/ the rest of your oil and see if it "cleans" up anything? Though not the same as arx, it's ester base stocks should have some solvency. If you've just been doing short interval M1, there really shouldn't be much to clean, though. Some engines do burn a little oil. Have you been on a SRT4 web forum to compare w/ other owners w/ the Mopar upgrades?

 

[Idrinkmotoroil]

quote:

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Originally posted by VNT:
Your running a Stage 2, you aint got no warrant LOL?

Have you checked your PVC, any oil in your intercooler?? Do you run a catch can?

I run Amsoil 0w30 with 7500 miles intervals on a Stg1 in my PT GT, doesnt use any oil.

My guess is since your running more boost and probably enjoying the stg2 your running WOT a little bit more often.

Try a different oil or try for one interval of 3000 miles keeping it normal and see if the consumption goes down. Do you have HOM with your kit??

---

yeah I think if you sneeze the wrong way DCX will void your warranty regardless. lol.

I really don't push it very hard in daily driving, if I did I would think it was normal to consume a bit of oil but I drive it pretty easy with little boost most of the day.`

I know the intake is a big source of oil consumption, I had the typical oil drip at the cold side intercooler piping where oil drips down from the throttle body. I don't have a catch can but its a good idea.

I'm going to switch oils for a bit, I've heard good things about Amsoil and low consumption. I've been running slightly colder spark plugs but I'm going back to the stock heat range in an effort to burn more fuel mixture.

thanks

 

[VNT]

Your running a Stage 2, you aint got no warrant LOL?

Have you checked your PVC, any oil in your intercooler?? Do you run a catch can?

I run Amsoil 0w30 with 7500 miles intervals on a Stg1 in my PT GT, doesnt use any oil.

My guess is since your running more boost and probably enjoying the stg2 your running WOT a little bit more often.

Try a different oil or try for one interval of 3000 miles keeping it normal and see if the consumption goes down. Do you have HOM with your kit??