What are your opinions on Gunk's 5 min Motor Flush? My engine had a lot of build up and I used a can of it. I was going to use a second application, but figured I should ask for your opinions before I dumped another one in. It seemed to make a big difference with the first. I was able to lean out the carb, which was burning rich in order to keep it running. The oil that had less than 300 miles on it came out coal black. I know the engine was bad enough to warrant the use of a second can, but I have never used the stuff before and wasn't sure if I would be doing more harm than good in the long run. Thanks,

Mike

 

does it say anything on the can about using a second application? if not, is there a number to call on the can? maybe they can answer that question. i dought it will hurt to use another can.

 

It says another application may be necessary for high mileage/dirty engines. I was just wondering if anyone had used this stuff before and had any bad/good experiences. Thanks for taking the time to respond.

Mike

 

are you satisfied with the first application? i think i might try it on my truck. did you say you had to lean out the carb as a result?

 

I was pleased with the results. I had to run the carb rich to keep it running evenly, which gave off that sickening exhaust smell (no way to really describe it). After the application, I was able to back off on the idle mixture, set the timing to specs, and get rid of the foul exhaust fumes. It runs smoothly and starts up on the first crank each morning. I really did it because I pulled off the left valve cover and saw a mess. I hate a dirty engine and was going to pull the heads off to have them powerwashed/tanked at the local machine shop. A friend of mine suggested to try this stuff first.

Mike

 

Hi, I have used it several times and have had good results. However, I must add that I have heard stories of it supposedly making gaskets leak. But you know how that goes, someone always has a complaint about something, and their gaskets may have already been leaking(just got filled with crud and seal off)and the gunk just cleaned out the leak pathway a little better. t wice should not hurt just don't leave it in over 5 min. In other words follow the directions to the letter.
Vic

 

cool i think i'll give the stuff a shot this weekend and see what happens, if i can lean out my carb it might get rid of my backfire problem. i'll cross my fingers... mocky

 

THIS STUFF WORKS GREAT,BUT BE SURE TO CHANGE THE OIL AT LEAST TWICE TO FLUSH THE SLUDGE FROM THE BOTTOM OF THE OIL PAN.I CHANGE MINE ONLY ONCE AND I HAD SOME LARGE CHUNKS GET SUCKED UP INTO THE OIL PUMP PICKUP SCREEN AND CLOGGED IT UP,GIVING ME LOW OIL PRESSURE.I HAD TO PULL THE PAN TO CHANGE THE PUMP, BUT I JUST CLEANED OUT THE SCREEN AND MY OIL PRESSURE WENT BACK UP.SO FLUSH THE ENGINE OUT GOOD WITH 2 OR 3 FREQUENT OIL CHANGES.IT EASIER AND CHEAPER THAN HAVING TO PULL THE PAN LIKE I HAD TO.

 

How soon after would you recommend the second oil change?

 

In June 99 I became the proud owner of a 68' F100 with a FE series motor that was in poor shape. The previous owner had not changed the oil in 4 years and put around 3,000 miles on it. I started with flushing the motor and adding CD-2 detergent. I have changed the oil 5-6 times since. Just did the 3rd motor flush yesterday. After running the 5 minute oil flush I let the engine sit over night to get as much out as possible. When I started in June the lifter noise was real bad. Now it is nice and quiet with just a little tapping now and then. Yes I found lots of oil leaks. A good steam cleaning and new gaskets/seals have helped. Oil pressure is up and the motor runs great. I did add a new timming chain set and various other "tune up" parts. Use some cheap oil after the flush and drain it the next day or so. Then change over to your favorite brand with a fresh filter. And look for those leaks. They will come.

Good luck!

68' 2WD F100 352-390(?), T-18 4SPD

 

I would not use it. did once, the pickup sreen on my oil pump plugged up and my engine was shortly toast.Ill just pour sand in next time. I think the best way to clean an engine is to do extra oil changes about 3 in a row at about 500-1000 miles apart.I have had luck with Rislone for sticky lifters though.

 

I just did my third flush this evening and will drop the pan tomorrow to check out the pump and screen. I am having problems with the oil pressure, so from what I gather from the helpful folks around here is my engine may be on its last leg. I figure I might as well get it cleaned out as much as possible before the eventual rebuild. Thank you all for your input.

Mike

 

I bought a 79 f150 4wd used used in 1984, that had 65, 000 mi. on the 351 mod. It run good and strong with no smoke out of the dual pipes or any bottom end engine noise typical for the 351m's of that era. I replaced the valve cover gaskets that were leaking and noticed it also a lot of sludge on the heads. I purchased a qt. of the "Gunk" and followed the instructions, running for 5 min, and changed filter and oil again. My oil run cleaner, buuut, within two months and about 2000 mi, it started getting the bottom end noise and blue smoke out of the duals when accelerating and deaccelarating. I talked to a top mechanic and a engine rebuilder and they both told me the same story. They said the "Gunk" was really almost like kerosene heater fuel. It is a fast acting agent for degreasing and deoiling metals. They said when a engine is new, the manufactures of that day had all engines new, be broke in with a light viscosity oil the first 500 mi. This allowed a oil "film" to impregnate and bond the tight machine tolerances in the rings, journals, and mains, bearings etc. They said the kerosene cut out this protective film and was causing failures in these parts. I did not have the engine taken down to see if they were right, I traded it for a work van. But, with those guys advice in mind,I will sure not use it on the 79 f150 351m 4 wd, granny gear 4sp. am restoring now, good luck on your engine.

 

My brother owns a Chevy and did two applications, a week later he had to pull the motor because it ##### the bed, I told him to by a Ford,...hehehehehheheheheh


Scott

 

Don't any one use it its Crap!!Change your oil more often so you don't get a dirty engine in the first place. and don,t buy a vehicle with black cruddy oil in the pan.