compression test on 5.7 hemi
#11
Join Date: Jul 2007
Location: South Georgia/East Florida
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Born in Chicago in 1923, Marvel Mystery Oil was developed to combat deposits on carburetors caused by poorly refined gasoline of the age. Marvels popularity soared as word spread of its effectiveness in treating all types of engine ailments and was used extensively in WWII on everything from airplanes to battleships to tanks.
But don't overdo it, the stuff works well and could break loose a lot of carbon build-up at once and give you a sludge issue...
#12
Just beware of that Marvel Mystery Oil. I had a V8 once with only 140k on it and added some in the crankcase. It broke loose all that carbon buildup and it drained to the oil galley in the block and pluged the drain holes to the pan so the pump pumped all the oil to the top of the motor and none was getting back to the bottom. In the end I ended up with a bad knock with 2 spun main bearings and one destroyed crank.
On a side note, I agree with how Dirty said to do the compression test but when you are getting a big difference in numbers arent you also supposed to add a small amount of oil on the combustion chamber and then do the test again to help seal the rings and check for gap (blow-by) issues?
On a side note, I agree with how Dirty said to do the compression test but when you are getting a big difference in numbers arent you also supposed to add a small amount of oil on the combustion chamber and then do the test again to help seal the rings and check for gap (blow-by) issues?
If Marvel Mystery oil did that to your engine, that means the engine should have been broken down and properly cleaned/rebuilt. I used Marvelmystery oil in Several engines with zero problems. I would never pour Seafoam in my crankcase. That's like pouring in water. No thanks. Clearly if Marvel removed all the deposits it works well. Also, if the carbon built up and clogged the oil galley holes in the heads, you would have had lots of blow-by, an oily air filter and a clogged PCV valve. If you stay ontop of the PCV valve none of those problems would have occured. This keeps the pressure and flow through out the engine. With Lucas in the fuel, that will aid in the removal through buring the carbon in the cylinder which will remove any deposits out the exhaust instead of keeping it internally in the engine. I'm thinking he has a problem with one cylinder possibly 2. he only has 50kmi so it's not the same as 140kmi. Also, 50kmi on an '07 is a bit of highway travel. Not city travel stop/go which creates much more build-up.
You are corect on the oil in the cylinder. Anyone doing the testing would know how to do that. i wasn't gonna go into detail because he wasn't doing it himself.
#13
Thanks, Ive built a few engines in my day. I know if the internal of that engine had to be bad if that Mystery Oil did that but I just wanna point out what can happen. Who really knows what the inside of an engine looks like without breaking it down. So my point is you are taking a chance.
Get off my nuts about sentence structure. Hell, it was only two run-on sentences.
I dont do Seafoam either. The only way I would do it was if I had a crap engine that I took apart, seen what the condition was, put it back together, ran it with an additive (seafoam) and then broke it back down again to compare.
Get off my nuts about sentence structure. Hell, it was only two run-on sentences.
I dont do Seafoam either. The only way I would do it was if I had a crap engine that I took apart, seen what the condition was, put it back together, ran it with an additive (seafoam) and then broke it back down again to compare.
#14
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I do Seafoam in the gas once in a great while, about oil change time. I've always mixed some with my 50/1 mix for my chain saws, weed whackers, etc. and have had great luck with it keeping the internal really clean. I've got some things at the farm, tillers, weed eaters, etc, over 20 years old, used hard on those 38 acres over the years, still run like a top...
Also a huge Marvel fan, it's the only thing we use when we swamp a four wheeler. The water molecules bond to it and it takes it right out of an engine. Anyone wants a sure fire way to get a swamped engine back to perfect running condition, PM me BEFORE you hydrolock the thing, we've got it down to a routine...
Also a huge Marvel fan, it's the only thing we use when we swamp a four wheeler. The water molecules bond to it and it takes it right out of an engine. Anyone wants a sure fire way to get a swamped engine back to perfect running condition, PM me BEFORE you hydrolock the thing, we've got it down to a routine...
#15
You had better leave one plug in each cylinder on the Hemi or you will have 0 compression
There is a catch 22 to the warm engine thing because it is always recommended to only remove spark plugs from aluminum heads when cold!!
Confusing
#16
The plug removal part you have sorta correct. the reason they say don't remove the plugs when warm because aluminum expands and the block almost squeezes the plug threads, so you can shave a miniscule amount off the threads. The biggest thing is when you put the plug back in.. Stripping it. it's very easy to strip the plug threads on a warm head.
#17
im not mechanically inclines at all thats y i asked u guys for help. figured the dealer was takn me for a ride. so dont know what there test involved. the dealer acted like they found nothing wrong so they called chrysler. chrysler said i need a valve job, lifters, and something done with heads. they never evn seen the damn truck. sounds like they came to the conclusion based on what dealer told them. who knows if dealer told them it only does it for 10 minutes or if they told them it does it all day. dont know.
#18
im not mechanically inclines at all thats y i asked u guys for help. figured the dealer was takn me for a ride. so dont know what there test involved. the dealer acted like they found nothing wrong so they called chrysler. chrysler said i need a valve job, lifters, and something done with heads. they never evn seen the damn truck. sounds like they came to the conclusion based on what dealer told them. who knows if dealer told them it only does it for 10 minutes or if they told them it does it all day. dont know.
i wouldn't tell the dealer at all about putting Marvel Mystery in the crankcase. They will give you a whole line of BS if you do regardless if your covered under warranty or not. they are going to want to save their butts on diagnosis and don't want to lose business. You don't need to be a mechanic to pour in Marvel mystery oil. I would recommend taking off your oil filter to remove some oil. You should get about 1/2qt all said and done. Then just pour a qt of Marvel in. So what about being 1/2qt over for one oil change. it's worth a shot right???
#19
i had a misfire code on #4 and 6 cylinders. took it to the dealer under warranty, and predetonation blew holes in both pistons. it still ran, just shook like it had a big ol cam in it or something and was pretty weak. they pulled the engine out and rebuilt those 2 cylinders under warranty. what i didnt tell them, was that i ran 87 in it for one whole summer when fuel prices were up. after they had it put together, he said to run 89 octane or better at all times, period and it wont have any more problems.
sounds like you are having issues with the same 2 cylinders, my dealer said they have seen cylinders 4 and 6 go before due to predetonation.
sounds like you are having issues with the same 2 cylinders, my dealer said they have seen cylinders 4 and 6 go before due to predetonation.
#20