JCON

I have a 2005 Mustang GT with 66,000 miles. Last November I had a local FireStone (friend) install suspension parts over the Thanksgiving break. I asked him to swap the oil filter since the oil only had 6-7k miles and I usually run once a year or 15k (which never happens). Left him two quarts of synthetic. When I got the car back he said the oil was really low. Never having burned oil before I figured he just poured more out of the filter than he thought. Over the next week I added 3 more quarts of oil before it registered on the dip stick. So I was obviously running dangerously low. I've owned the car for a few years now and it never burned oil.

A few weeks ago I was headed down to a big car show about an hour and half away. After the car was warmed up, I got in to it with a New Edge Cobra. My friends behind me said they saw a small puff of smoke when I went WOT. I did not want to hear that because I had noticed in recent drives that the smell from my exhaust had changed slightly but I couldn't pin it down (I haven't had cats on the car for several years). I put some Restore in the oil and no one saw the smock again after that. Now a few weeks prior to this trip I installed under drive pulleys, charge motion deletes, and an intake and then had it dyno tuned.

Fast forward to tonight, hoping for a valve issue, i finally got my compression test adapter in (because no off the kit shelf was designed for the Triton engine). The cylinders read as follows:

C1:185
C2:185
C3:185
C4:140
C5:180
C6:185
C7:180
C8:190

So then I wet compression tested Cylinder #4... 185…

My worst fear was then realized. I just dumped a bunch of money in to the car and now I have to rebuild it. For the record, I don't have smoke coming out of the exhaust, even under load, other than that one day. I don't have any misfire codes and all of the spark plugs look equally dirty. I have had a JLT oil catch can on the car for almost three years and it has never caught and appreciable amount of oil (to the point where I haven't dumped it out, I just wipe it clean with a single paper towel).

I have heard of a few things to make sure its not just a bad seating or carbon build up:


Method 1: with car on, let the vacuum hose suck up 1-2 Gatorade caps of water for each cylinder, reconnect line, and run the car hard to get engine temps up. Water will turn to steam and force it's way past the ring and clear out and debris.

Method 2: pour 3-4 oz of ATF in to the cylinder, reinsert spark plug and turn the engine over a few times to force it in to the rings. Let sit for 48 hours so detergents can work away at carbon buildup. Drive car at freeway speeds for 15 minutes to burn off excess.

Method 3: with car on, slowly pour 1/3 of a can of SeaFoam into the vacuum line so the idle is rough but not to the point of stalling the car, shut car off and let sit for 10 minutes. Reconnect line, and run the car aggressively for 5-10 minutes. This will deep clean engine and breakdown deposits that could cause an improper ring seating.

Method 4: Start the engine and get it up to temperature. insert the vacuum line into the bottle of cleaner. Shut the engine off and remove the spark plugs. Squirt some cleaner in each cylinder. Let it soak for 1 hour. Crank the engine with the coil disconnected to clear the cylinders. Replace sparkplugs and start the car. Run at 1,500 -2,000 rpm until engine hits operating temp again then do 2-3 WOT runs from a slow roll 10-20 mph up to highway speed.

Before I look at the unfortunate cost of pulling the engine, I want to try any driveway mechanic methods. Has anyone tried any of the above or have any other tricks to try first?

Sucks a lot because I just put all those parts on and paid $300 to have it tuned and it runs strong and it's definitely fast and now I confirm what I was told months ago... Thanks.

charliebrown266

I would try some seafoam! stuff works really well!

JCON

I am going to grab some tomorrow. For now, after talking to a few 'old' mechanics, I have put some ATF in the the cylinder and turned the engine over to let it drip down the walls more. Literally, it's dripping down my garage wall. Didn't thin of the force of the starter and it shot some of the ATF out of the cylinder... Will report back. He said that this can clean debris if that is the issue which can be caused by low oil (time leading up to November) or running too hot (after two revisions of the tune were loaded, my car through a passenger cylinder head temp warning MIL but it didn't come back while driving).

Nuke

I believe #3 is described on the Seafoam can. Keep us posted.

moosestang

I would just keep running it till it starts smoking or is noticeably without power/misses. I'm not convinced seafoam does anything. I just got the berryman b-12 chemtool total comustion cleaning kit off amazon.com for $13. I think it's just another variation of seafoam with slightly different chemicals, but the reason i got it is because it comes with a tube that insures you don't suck to much in at one time. I'm going to take a video inside the cylinder before an after. Like this.

algregory

I've been a fan and user of "Tufoil" for about 18 years. I had a BMW set up for road racing, the machinist that built my engine recommended it. That engine went from 132k to 269k with a total tire consumption of 29 sets of performance rubber. A very sweet engine until I sold it before moving. My '89 GMC 4.3 liter PU has 238k on it, its been on an Amsoil and Tufoil diet for a very long time. Runs great, doesn't smoke, start-up or running. FWIW

Will using Tufoil help with an engine that burns oil?
Many old engines show signs of oil burning. Tufoil can help in some cases by freeing up partially sticking piston rings. There have been some dramatic improvements reported from the field where Tufoil freed up the rings and they started working properly again. However If the rings are cemented solid in their grooves or the cylinder is scored, no lubricant can eliminate the smoking.

JCON

Got some good news! Last night I tried method 2 but with far less than the recommended amount of fluid since I didn't have a way to measure it and it only sat over night. Dry tested the cylinder after work today and my compression was up above 165 (increase of 25 psi) and the next cylinder was 180. The car felt much smoother and idle was also improved. I went out and bought a small 1 oz measuring cup tonight. Tomorrow morning I will redo this method with 2-3 oz and let it sit for two days. Fire it up and test it Monday morning and report back.

This is encouraging news vs building a new engine or trading the car... It's also encouraging because my car made excellent power while one cylinder was low on compression. Would love to see it with full compression and a few more ponies

I'll have to look in to Tufoil. I've always run AMSOil and just recently started running Restore which has been great on previous cars. I've also had great results with SeaFoam in the gas tank but have never used it anywhere else.

moosestang

So you poured some ATF into the spark plug holes? Was that with the car hot or cold? I don't think I'd ever heard of that.

Maybe PB blaster would work better! It's always worked great for loosening stuck bolts. It might foul your plugs and o2's though.

JCON

The car was warm when I did it but I don't think it matters when you do it. The key is to do it, then crank the engine a few times to let it coat the cylinder walls.

I redid this Friday night but measured 1oz (not 2-4 oz like the guys said... made me nervous). Let it sit two days then fired it up this evening and it was between 165 - 167 psi. The cylinders from rear to front next to it read 180, 185, and 185. So Doing it a second time didn't net any real difference but doing it once got it from 140 PSI to 165 PSI. I am now a less than 11% variance from high to low. Car sounds like it's happier and does feel smoother so that's a plus. As for future readers, I mark this a solid and cheap method to clean the rings and cylinders before tearing it down.

moosestang

What all did you have to get in order to do a compression test? did you do it with the engine hot, 1 spark plug at a time? I'm just curious about the procedure you used.

I googled pb blaster to free up stuck rings and sure enough, people use it. Next time I'm due for an oil change, I might spray some into a cylinder to see how it does agains carbon on top of the pistons. I'll be sure to do a before and after video.