sludge is your friend sometimes

[ricosuave420]

not i can vouch for this, when i got my car from my dad hes always ran standard motor oil, aka non-synthetic, bc nothing on the engine leaked, then when i put synthetic in despite my dad telling me is was a bad idea, so i put it in and 2 days and 30 miles later i hear knocking and find that the synthetic is to thin so i put regular oil back in, and when i took out the synthetic out is was dirty as ever, and after that synthetic change my car now leaks a little oil on the driveway, so i suspect that the sludge was filling in the cracks, and the synthetic cleaned it out so now i leak oil, so syntheic is not always good and sometimes sludge is your friend on an older car

[grandprix104]

I have heard similar things before. It is not that uncommon I guess.

[repinS]

Knocking? You sure something else isn't catastrauphically wrong with your engine?

[00Beast]

No, sludge is not good. If it's holding your gaskets together, imagine what it's doing to your oil passages, lifters, rockers, etc. Fix your gaskets and run synthetic, it'll be better in the long run.

[LeSabre in Buffalo]

Synthetic's cleaning abilities come from the additive packages in the oil, not because of being too thin. An example is Castrol Syntec 0w-30 being practically a 40-weight, while regular Havoline Deposit Shield 5w-30 is a 20-weight for all intents. Synthetics generally have more expensive and slightly more robust additive packages. It's the additives doing the cleaning, not the oil being too thin. You know the Pennzoil commercials claiming sludge cleaning? It's all in the additive packages, and how Pennzoil Platinum has a different additive package than regular Pennzoil.

Clean that engine up. The sludge will keep the oil from getting to necessary parts. Marvel Mystery Oil for an oil change works well, as does Auto-RX. A Seafoam flush might knock too much loose at once. The others will clean up the sludge much more gradually and safely.

For the noise, has it returned? And what kind of noise was it?

[xX3800Xx]

No, sludge is not good. If it's holding your gaskets together, imagine what it's doing to your oil passages, lifters, rockers, etc. Fix your gaskets and run synthetic, it'll be better in the long run.

No it wont. Hes better off to keep the conventional oil in and just stay away from synthetic until hes ready to sway in a lower mileage motor that doesnt have any sludge or completely rebuild his current motor.

If you want to slowly get rid of sludge rotate between oil brands as they each have different additives.

[ricosuave420]

well the second i got rid of the synthetic the knocking went away imediatley, and one day soon i plan on completly rebuilding my engine, and i plan on stayin on regular oil until that day

[Ol' Timer]

sometimes sludge is your friend on an older car

Yikes! What's in YOUR Transmission???

[wjcollier07]

Oil leaks get worse with synthetic because of the significantly higher levels of detergents present.

My leaky oil pan and valve cover gaskets have gotten slightly worse since I switched to Pennzoil Platinum in the SSE. But I know its a good thing, because I know its just removing crap that's all been adding up over the years of running conventional crap. (Sorry, I'm a big fan of synthetics) I've been running the PP for 500 miles, and already the oil is about as dirty as the truck's Amsoil after 16,000 miles....there was crap hiding in there.

On a side note...the truck's got 72,500 miles now, with a little over 16,000 miles on this oil change and doesn't leak a drop, and has been running nothing but synthetic since 31,500 miles. If your engine's seals are kept clean and well conditioned for their entire life, there's really no reason for them to degrade and allow leaks. I will share that I've seen identical 2004 5.3 engines with the same ~75,000 miles come into Sears for oil changes, that run on nothing but conventional, and I can confirm, the majority of times, they do have minor oil leaks. Some of the corvettes that come in that require Mobil1, a couple of our good customer's engine's have over 120k miles, running Mobil1 since the first second the engine was started, and I've yet to see any of them with any present oil leakage. Coincidence? Maybe. You decide.

Good synthetics with high quality additive packs simply keep contaminants suspended, allowing to be caught by the filter, instead of settling and embedding in soft materials (i.e. gaskets)

[ricosuave420]

well i have no idea what my trans looks like, my dad had the old one rebuilt with new everything, so it cant look that bad can it?

[bonnevillain]

No way to know without checking.

[ricosuave420]

yea you know me, i take my transmission appart on a daily basis lol, cant i just loot at the fluid to see if its clean or not? o and i herd it was bad for a transmission to change the fluids because it can knock sediment loose and mess everything up, is that true?

[LeSabre in Buffalo]

How long ago was the rebuild? I'd still say flush your transmission if you haven't done it in the last 50k miles.

[ricosuave420]

it was done about 5 years ago, and i have no idea how many miles its been, i would think its prob over 50,000 miles

[00Beast]

The old wive's tale about chaning fluid is just that. If you have 250,000 miles on a transmission, and you change the fluid and it dies a week later, it was going to die eventually, but that old fluid was probably holding a bunch of clutch material, causing decent shifts. However, when you put in new solvent fluid, it doesn't have that material in it, and is designed to keep the surfaces inside clean, so it eats away at what's left at the clutch packs, etc. Change your fluid with a good quality fluid at regular intervals, and it will go far. I only have 13,000 miles on my new transmission and I'm already planning on having it flushed with Amsoil Dex III equivalent, because I want this one to last at least as long as the other one did (144,000 miles). Changing the fluid earlier on a newer transmission is a good thing, as it gets all the metal and clutch material out from when the transmission was breaking in. You don't run oil in a fresh engine 5,000 miles, and you don't run fluid in a fresh trans 50,000 miles, IMHO.

[LeSabreUltra]

You should change your trans fluid at least every 15k in my opinion in these cars, and that's with a good aftermarket trans cooler. With Dexron VI you might be able to let it go a little longer. Before I had a cooler my fluid needed changing at 10k mile intervals.

Sludge is never cool! You always want your engine to look like this:



Well, minus the crappy intake gaskets of course.

And not like this:



Leaks or no leaks!

Of course, if sludge is keeping the engine and/or transmission together...you really have no choice but to keep it until you are able to fix it properly...

But there's no reason why you can't run synthetic on an older car. My LeSabre has 162k miles and it has run full synthetic since I got it at 128k miles. No leaks, and it's squeaky clean inside. I have great oil pressure and no knocks too.

Same for my S10 at 68k, I've run it on full synthetic since 38k...and it's a very happy 4.3.
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[00Beast]

My SSEi has 156k, and it's had synthetic since 139k. Not sure what was run in it previously. My parent's truck and suburban have had synthetic since new (suburban has 150k, truck has 58k), and they don't leak a drop, and won't for a long time.

[Ol' Timer]

Everybody has there opinion and no one is really wrong. My $.02 was to change the xmision fluid and filter every other year or 30,000 miles with Dexron III. My previous H-Bodies never pulled any loads up steep mountain grades in the summer so I did not see any need for a trans cooler. Just changing (not flushing) the xmission oil seemed to work for me. Your results may vary.

[LeSabre in Buffalo]

My transmission has seen 4 fluid changes since I got the car 2 years ago with 31k miles on it. Three with Dex-III, the last was a 13-quart cooler-line flush with Dexron-VI. I'm not changing the Dex-VI until about 100k since it's designed for 6-speed Allisons in diesel trucks pulling 10k behind them, not the 4-speed 4T65 in my car pulling me around. The Dex-VI is massive overkill for transmission protection and I like it that way.

[xX3800Xx]

My transmission has seen 4 fluid changes since I got the car 2 years ago with 31k miles on it. Three with Dex-III, the last was a 13-quart cooler-line flush with Dexron-VI. I'm not changing the Dex-VI until about 100k since it's designed for 6-speed Allisons in diesel trucks pulling 10k behind them, not the 4-speed 4T65 in my car pulling me around. The Dex-VI is massive overkill for transmission protection and I like it that way.

Actually Dexron VI is what comes in every GM transmission now. It superceeds Dex III. Its not massive overkill its just a better fluid.