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Sludge?

Old Nov 28, 2013 | 06:45 PM
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Sludge?

A question for any owners who work on their own cars that have higher mileage (60K+ miles): Do any of you have any sludge buildup in your engines? I'm at 95K and have been doing extended OCI (7.5-9K) with PU for quite a while now. I have not done a teardown but from what I can see through the oil fill opening and from dropping the lower oil pan once, it's as clean as the day it was assembled. I want to make sure all the internals are as clean as possible before going FI whenever GTM finally gets the parts ready. I'm just curious if anyone else has had sludge issues.
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Old Nov 29, 2013 | 03:52 AM
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Nothing here. Im almost at 120k and my dyno numbers are 1:1 with a 2013, also my cylinder compression is great. Youll be fine BB.
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Old Nov 29, 2013 | 08:07 AM
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Thanks. I will do a compression test as well. But wondered if our engines are probe to sludge because what I can see if mine is incredibly clean. All I've done is a couple of seafoam treatments and used top quality oil, but with pretty long OCI.
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Old Nov 29, 2013 | 09:09 AM
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Nissan says 7.5K on interval for no sludge...

So I'd say your on par...
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Old Nov 29, 2013 | 10:32 AM
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This should help

http://www.howstuffworks.com/5-sympt...its.htm#page=4
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Old Nov 29, 2013 | 11:01 AM
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Thanks. I know what sludge does to the engine, what causes it, and how to avoid it. I don't think that I have a problem. I 'm just asking if anyone else has had the issue. Have you?
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Old Nov 29, 2013 | 11:25 AM
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Based on my understanding, the primary causes of sludge include:

-Water vapor in the crankcase caused by condensation. This can be more problematic if most of your driving consists of short trips and the moisture doesn't have time to evaporate.

-Blow-by from the combustion chambers. This problem is compounded when you overfill the crankcase (oil will foam, decrease lubrication and increase damage from blow-by exposure).

-Heat, which is probably the most common cause such that at high temps, non synthetic oils start to oxidize and create acidic byproducts. This is especially problematic in small turbo charged engines which run hot by design.

Last edited by socketz67; Nov 29, 2013 at 11:35 AM.
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Old Nov 29, 2013 | 11:35 AM
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No sludge here. 53K miles.
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Old Nov 29, 2013 | 11:52 AM
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Originally Posted by socketz67
Based on my understanding, the primary causes of sludge include:

-Water vapor in the crankcase caused by condensation. This can be more problematic if most of your driving consists of short trips and the moisture doesn't have time to evaporate.

-Blow-by from the combustion chambers. This problem is compounded when you overfill the crankcase (oil will foam, decrease lubrication and increase damage from blow-by exposure).

-Heat, which is probably the most common cause such that at high temps, non synthetic oils start to oxidize and create acidic byproducts. This is especially problematic in small turbo charged engines which run hot by design.
Thanks for the explanation. Do you have any in sludge your VQ? Mileage?
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Old Nov 29, 2013 | 12:16 PM
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Mine is a 13', so I'm still running on the break-in oil and sludge isn't an issue at this point. I put 100K on my 04 and didn't have a sludge problem, so I'm pretty confident that this isn't a problem with the VQ.

I know that Audi/VW have had problems with sludge on their 1.8L turbo charged models. The only problem I'm aware of with the VQ37VHR is the fact it is not that competitive when it comes to gas mileage. Long stroke, large bore, high compression NA engines typically suffer this fate.

Hopefully the patented diamond-like carbon (DLC) coating will help internal heat/friction and contribute to less sludge over time: http://www.nissan-global.com/EN/TECH...RVIEW/dlc.html

Last edited by socketz67; Nov 29, 2013 at 12:33 PM.
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Old Nov 29, 2013 | 06:31 PM
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Have almost 90k on my 09-am running Mobil One EP with 10kmi change intervals.Just looking thru the oil fill it's as clean as the day I got it-I've got pretty good UOA also.
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Old Dec 17, 2013 | 10:44 AM
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I just traded my 07 G35 coupe and it had 97K miles on it and no issues. Still ran strong (maybe better than mu 2013 IPL! i only use synthetic oil though since i was a past Audi A4 owner with the 1.8 Turbo engine and had a oil sludge issue. They had a design issue and if you didnt change every 3K miles it might get you and i usually did 5K changes and at about 52K miles i had to replace a engine and turbo to the tune of $8500 out of warranty! When you opened the oil cap it looked like black thick spagetti in there. There was eventually a class action suit with VW/Audi America a few years back and i actually got 1/2 of it back! Christmas in July! if i had kept all my old receipts i would have gotten 100%. From then on i have only used synthetic oil hoping it would prevent the oil from breaking down. Has served me well so far.
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Old Dec 17, 2013 | 10:54 AM
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Originally Posted by Pnrymmf
I just traded my 07 G35 coupe and it had 97K miles on it and no issues. Still ran strong (maybe better than mu 2013 IPL! i only use synthetic oil though since i was a past Audi A4 owner with the 1.8 Turbo engine and had a oil sludge issue. They had a design issue and if you didnt change every 3K miles it might get you and i usually did 5K changes and at about 52K miles i had to replace a engine and turbo to the tune of $8500 out of warranty! When you opened the oil cap it looked like black thick spagetti in there. There was eventually a class action suit with VW/Audi America a few years back and i actually got 1/2 of it back! Christmas in July! if i had kept all my old receipts i would have gotten 100%. From then on i have only used synthetic oil hoping it would prevent the oil from breaking down. Has served me well so far.
Damn. Sucks about you Audi. Expensive lesson.

I really want to know primarily about experiences only with the current generation VHR engine though as that's what relates to what I'm specifically curious about. The HR is pretty close though. I guess I should just do a compression and leak down test and go from there.
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Old Dec 17, 2013 | 12:46 PM
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115k on the clock and engine is still running strong with no sludge. 7k intervals on redline oil. I do seafoam like once a year which prob helps.
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Old Dec 17, 2013 | 07:49 PM
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I had a 1985 MR2 with 185K on it. The oil/filter was changed every 10K with Mobil 1. The last time I checked the valve shim adjustment at 180K everything looked like freshly machined aluminum. YMMV.
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