Bought an 88 Sierra 305 with 67k miles on it. Valve seals were bad. I started using Mobil 1 at 34K intervals immediately. At 97K opened it up to fix the seals and found the heads covered with sludge which was heavily eroded (looked like the badlands of South Dakota). Opened again at 12K due to leaking valve cover gaskets and found the heads clean as a whistle. Bottom line: Mobil one will remove sludge, somewhat slowly.
synthetic oil cleans the engine ?
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Originally Posted By: Steve S
The polyol ester and diester base stocks are the cleaners in the syn world polyalphaolefins not really.
Syn by itself will leave minor deposit in an engine over a period of time. So it makes sense that at best it will not allow the deposits to get worse. (IMHO)
The polyol ester and diester base stocks are the cleaners in the syn world polyalphaolefins not really.
Syn by itself will leave minor deposit in an engine over a period of time. So it makes sense that at best it will not allow the deposits to get worse. (IMHO)
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Originally Posted By: dickwells
Bought an 88 Sierra 305 with 67k miles on it. Valve seals were bad. I started using Mobil 1 at 34K intervals immediately. At 97K opened it up to fix the seals and found the heads covered with sludge which was heavily eroded (looked like the badlands of South Dakota). Opened again at 12K due to leaking valve cover gaskets and found the heads clean as a whistle. Bottom line: Mobil one will remove sludge, somewhat slowly.
When was this, though?
Bought an 88 Sierra 305 with 67k miles on it. Valve seals were bad. I started using Mobil 1 at 34K intervals immediately. At 97K opened it up to fix the seals and found the heads covered with sludge which was heavily eroded (looked like the badlands of South Dakota). Opened again at 12K due to leaking valve cover gaskets and found the heads clean as a whistle. Bottom line: Mobil one will remove sludge, somewhat slowly.
When was this, though?
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I bought my Mustang with 235,000Km on it (IIRC). I have no idea what oil was run in it.
I switched it to M1 5w30.
Within a week, both (cork) valve cover gaskets were leaking.
I let it go for a month or two.
Pulled the upper intake, pulled the valve covers and replaced the gaskets with new rubber-impregnated Corteco ones.
Rockers had some varnish on them, but these engines aren't known for gooing up under the valve covers; the real tale is the lifter valley.
Ended up replacing the rear-main seal, which had started weeping.
A couple of YEARS later, and I had run:
M1 10w30
M1 0w20
M1 5w50
M1 5w30
through the engine and racked the mileage up to the 300K mark.
Fill in the sump was 5w50 at the time. I pulled the entire top-end to do heads/cam/intake.
Heads were cleaner than I remember; no varnish on the rockers anymore.
Lifter valley was spotless; you could eat off it. My old trucker friend was flabbergast.
Cylinders still had visible cross-hatching (common with 302's) no ring-ridge...etc. Lifters were easily removable from the bores; no varnish on them.
Ported GT40's were installed, TFS #1 camshaft, 1.7 roller rockers, new pushrods, TFS-R intake and the like.
Car went to the dyno, made 270RWHP and was PIG rich at a 10:1 A/F. Car needed smaller injectors (30's were on it) or a chip for the ECM; was using a calibrated MAF at the time.
At 330,000Km, I wrote the car off.
Engine was pulled. Stuck in the Capri.
Bought a custom cam for it.
Tore off the front dressing and the intake to stick in a new cam and timing chain. This was at my good friend's parent's place, and another Mustang friend of ours was there.
The guy who's parents owned the yard, we had pulled his engine apart a few days earlier; he was building a new one. Spent it's life on Castrol GTX. Stuck rings on 5 cylinders, varnish on all the pistons, junk in the valley, varnish on the heads and rockers....etc.
When we cracked the lower intake off mine, BOTH of them said "HOLY [censored]! That's CLEAN!!!!" And I stated that THAT was why I run M1.
The ONLY other 302 I've had apart that was very similar in cleanliness was run on Amsoil, but that engine has half the mileage on it. I've posted pics on here.
So, yes, I believe M1 does some cleaning. But I also believe it takes time to do so.
I switched it to M1 5w30.
Within a week, both (cork) valve cover gaskets were leaking.
I let it go for a month or two.
Pulled the upper intake, pulled the valve covers and replaced the gaskets with new rubber-impregnated Corteco ones.
Rockers had some varnish on them, but these engines aren't known for gooing up under the valve covers; the real tale is the lifter valley.
Ended up replacing the rear-main seal, which had started weeping.
A couple of YEARS later, and I had run:
M1 10w30
M1 0w20
M1 5w50
M1 5w30
through the engine and racked the mileage up to the 300K mark.
Fill in the sump was 5w50 at the time. I pulled the entire top-end to do heads/cam/intake.
Heads were cleaner than I remember; no varnish on the rockers anymore.
Lifter valley was spotless; you could eat off it. My old trucker friend was flabbergast.
Cylinders still had visible cross-hatching (common with 302's) no ring-ridge...etc. Lifters were easily removable from the bores; no varnish on them.
Ported GT40's were installed, TFS #1 camshaft, 1.7 roller rockers, new pushrods, TFS-R intake and the like.
Car went to the dyno, made 270RWHP and was PIG rich at a 10:1 A/F. Car needed smaller injectors (30's were on it) or a chip for the ECM; was using a calibrated MAF at the time.
At 330,000Km, I wrote the car off.
Engine was pulled. Stuck in the Capri.
Bought a custom cam for it.
Tore off the front dressing and the intake to stick in a new cam and timing chain. This was at my good friend's parent's place, and another Mustang friend of ours was there.
The guy who's parents owned the yard, we had pulled his engine apart a few days earlier; he was building a new one. Spent it's life on Castrol GTX. Stuck rings on 5 cylinders, varnish on all the pistons, junk in the valley, varnish on the heads and rockers....etc.
When we cracked the lower intake off mine, BOTH of them said "HOLY [censored]! That's CLEAN!!!!" And I stated that THAT was why I run M1.
The ONLY other 302 I've had apart that was very similar in cleanliness was run on Amsoil, but that engine has half the mileage on it. I've posted pics on here.
So, yes, I believe M1 does some cleaning. But I also believe it takes time to do so.
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