Need advise on a piston soak
Hi all, I'm new here - first post. I need to ask about recommendations for a piston soak for my 1991 Mercury Capri XR2 Turbo, 1.6l DOHC Intercooled.
A little background:
I've had It for abut 4 years and have run it from right at 100k to about 148k now. It started using oil a few years back, didn't use more than most other cars I'd had, maybe 1qt/1800, but it began using about 1qt/1000 and I could see clouds when I accelerated hard- thick blue ones. I investigated and found out it was a bad turbo shaft and if I kept my foot out of it, the oil usage was not as bad, 1qt/1200, but if I floored it, I figured out it lost about a cup every time I did so, so I babied it for about 6 months until I could find the parts to replace the turbo.
With the new turbo on, I was still using oil more than I used to, just not so visibly (faint smoke on full throttle). I also had some nasty oil leaks and ended up pulling the head and sending it out for valve stem seals and a decking. I put ARP head studs and a Cometic head gasket on it along with all new seals last summer. That stopped the leaks, but the burning continued, but not thru the turbo and not thick blue.
Well, the oil consumption has steadily gotten worse. Back when I had the head off I did my own soak, not even knowing about what to call it. I just used sea-foam on the piston tops and tried to let it soak past the rings for a weekend, working the pistons up and down some.
IDK if it helped any, she runs terrific but still uses oil - now at a steady qt/500. I still see no smoke at startup, the induction piping is clean (not a turbo seal) and I see that it all comes through the PVC hose (blow-by). I have the best PVC valve recommended for it and have tried others, but none stop the flow. I put a catch-can on the line and I trap about a cup in 500 miles.
Oil history: After I got it I started using Mobil Super Synthetic, mostly 5W30 because of our cold climate in Michigan. Eventually, one mechanic I talked to convinced me to use a semi-synthetic high-milage oil like Valvoline sells which I am currently running (5W30 in winter, 10W40 in summer).
I started thinking how I might fix this and decided to try putting sea-foam in the crankcase 300 mi before a change. This didn't seem to help so for one more attempt I just put it in again and it is time to change it. That's when I came across all the info here on this site and started thinking about trying better solvents. I picked up some B-12 Berrymans, and just received a quart of Kreen I ordered last week. The eBay seller who sold me AC Delco Top Engine cleaner cancelled my order on me after receiving my payment (thankfully refunding me but costing me time getting started on this). I also read about some of you using Break-Free CLP gun cleaner so I received a shipment of that as well.
Should I order the AC Delco Top Engine cleaner again from elsewhere?
Here are my numbers...
Dry (cold too) CYL 1 (150) CYL 2 (149) CYL 3 (133) CYL 4 (155)
Wet (cold too) CYL 1 (172) CYL 2 (180) CYL 3 (170) CYL 4 (180)
She never smokes when starting, only when the RPM is in the 4000-6500 range and that is not much (light maybe blue, but faint). The other day she started on 3 cylinders and this rarely happens (might be a bad plug wire) and when it does it goes away in a minute. I was in a hurry to pull out of work and on 3 cylinders she smoked like a house on fire, but when I shut her off for a moment and restarted, she was back to normal and clear on 4 cylinders. That dosen't happen all that often, I should do a tune up though. She has about 30K on NGK G-Power Irridums, wires cap and rotor.
What kind of soak should I do? I was going to follow Trav's method, but I have the Break-Free, Kreen and BerryMans on hand, and the car currently has 3000mi oil in it (one Qt down - only a 3.4 quart capacity to start with so 2.4 in it and part of that is 180ml of Sea-Foam). I need to get started on this so any recommendation would be greatly appreciated...
Ron
First Post - First real piston soak
- Thread starter RapidCAD
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to the asylum! We’ve been expecting you! Nice car BTW.I'd honestly go for the CLP or Kreen. Doing what you are wanting to do is exactly what the CLP was engineered to do. I've seen CLP remove some really nasty, really hard, really caked on garbage.
Have you done a compression test? Were the wet numbers significantly higher? When you had the head off what did the cylinders look like? Could you see cross hatching, was there any ridge at the top?
I'm getting the picture of a small fun car to drive. Early turbo that liked being wound up. You bought a 23 yr old sporty car with a 100k of fun on it. Maybe the rings are coked in their grooves, but that supposes there are any rings left. It is only 4 plugs, do before and after compression tests. That will be the easiest way to tell if the soaks worked. What is the warm oil pressure at 3K RPM? Also Capris are very scarce up here where the roads are white with salt. And I know a guy who is deep into M3s who lamented his hotrod Capri that rusted to dust in Toronto. Meantime quick and dirty would be stepping up to 10w30 or even 10w40. I started my 350Kmile 528e full of dino 10w40 at 17 below. Should you not feel comfy with this, add a pint of MMO to thin out the oil and give it some gentle solvent cleaning. No experience with Kreen, reputed to be good. B 12 Chemtool is enamel thinner, but great in lawnmower carbs. Not impressed with Sea Foam. 10$ worth of smoke. Just my opinions, no data. Whatever you try,read the directions on the bottle first.
So out here, we can't get KREEN any longer ... It's some political B... about cancer causing chemicals, etc. Since non-licensed folks used it, the State said no more 
In lieu of KREEN, I use a combo of Break-Free and BG109. The Break-Free goes in overnight (or over weekend) and just sits. The end gaps will let it by to fill the whole ring pack. Then fire it up and drive about the block, change oil and filter and good to go.
The BG109 goes in (full can) somewhere between 500 and 100 miles before an oil change. Have had very good luck with this approach 
The next suggestion is to change the oil chemistry to break up the deposits. I'd run a change on Redline, then Pennz Ultra, then go back to semi-syn.
All this will do what it can. But you may just need a ring job ...
In lieu of KREEN, I use a combo of Break-Free and BG109. The Break-Free goes in overnight (or over weekend) and just sits. The end gaps will let it by to fill the whole ring pack. Then fire it up and drive about the block, change oil and filter and good to go.
The BG109 goes in (full can) somewhere between 500 and 100 miles before an oil change. Have had very good luck with this approach
The next suggestion is to change the oil chemistry to break up the deposits. I'd run a change on Redline, then Pennz Ultra, then go back to semi-syn.
All this will do what it can. But you may just need a ring job ...Try the solvents but I think your oil control rings are simply worn out or are coked. Consider the 148,000 miles with revs running at 4000-6000 rpm vs a V-8 that might not see 4000 rpm at all. Who knows what oil and OCI’s where used in the first 100,000 miles. Oil quality today is better than in 1991,
I rebuilt a Honda 1200 cc car engine and the ring lands were filled with coked oil residue. I had to use a chunk of ring to leterally bust out chunks of the residue. Rebuilding the engine might be a fun and rewarding project.
Some people use brake fluid. If I had reason to believe I had stuck rings, that's what I would use, (followed by water inspiration into the running engine at high revs and then an oil change), because I have some, and I've tried it as a carb cleaner in which role it seems to work quite well.
I currently have the high rev water inspiration underway as a general decoke but without the piston soak. Car seems to have stopped running-on on switchoff, but I need to distill some more water before I can step up the treatment intensity.
At nearly 150k miles maybe the bores and pistons are just worn. If that is the case no additives are going to help. Sounds like you have excessive blow-by, a classic symptom of worn pistons and bores.
How much is the car worth to you?, I dare say the work fixing the engine is more than the market value of the car, but what would it cost to buy another small, fun to drive car?.
Claud.
You might consider this to help with the compression issues and oil burning.
https://www.restoreusa.com/index.php
I've tried everything for piston soaks, except Kreen, and the clear winner on my oil consuming Corolla is Berryman B12. The stuff is STRONG. I actually had to pour oil in the cylinders to get it to start afterwards because I guess there was no oil film to seal the cylinders.
The results have been night and day. Hardly any more consumption and the pinging is now gone.
Previously, I've tried MMO, Seafoam, and Gumout Multi. They somewhat work, bu nothing like Berrymans.
You likely have worn rings. But just to make sure, did you clean out the intercooler or intake pipes after the turbo change. Lots of oil can reside in an intercooler.
I'd choose M1, 15W-50, and simply let your engine warm up.
Hmm, although I thought I checked the right boxes, I recieved no email notifications that ya'all had replied. Sorry about not getting back to this sooner, and many many thanks for all the interest. I will try to answer a few points but my lunch is almost over!
The compression tests are in the OP (sorry I'm long winded). When the head was off there was a small ridge but it appered to be mostly deposit. No I didn't see cross hatching if I remember correctly, but I'm not really a engine building kind of guy, so I didn't take note of it although the more I think of it, I saw that somewhere, maybe my bores did reveal that. I'll have to review the pix.
I have a feeling that this could be just wear, but I'm going for the soak and crossing my fingers. Unless one of you says DON'T DO THAT!, I'm aiming at:
dumping one more quart out of it,
Putting in two fresh quarts and maybe 1/3 can of B-12, ( not sure about running the pre-soak with my Sea-Foam already in there and not sure about using half a can in a 3.4 capacity engine). Although I'd like to run 1/2 can in the pre-soak.
Run the engine with the B-12 in crankcase for 30 min at idle, shut it down, pull plugs.
Soak each cylinder with 2oz of CLP for 2 days, turn crank both ways, suck out why is left and change oil and filter.
Reinstall plugs, pour 1/2 can Berrymans in gas tank, start her up. Rev her for 5 min @ 2k, then idle for 20 min and shut it down again.
Dump oil change filter again. Put in 10w40 semi-syn and drive a tankful.
Lastly, put half can Kreen in crankcase and other half in gas tank and in 1000 miles, change oli and filter again.
Sound good?
Oh, yeah, and the intercooler did have a good 3 pints in it when I replaced the turbo two years ago. It is clean these days because I know my intake shows no traces of oil anymore. Oil is all migrating from valve cover through PCV valve hoses and catch can into intake manifold vacuum port.
I must get better at reading closer. 30 psi diff between dry and wet. Definitively, try the solvents in both fuel and oil. Start with a thicker oil to keep the bearings happy and juice away. Please report back results. IF you can get the compression rings loose, it can be proven with a comp test.
MolaKule
Staff member
I still recommend LCD, Inc.'s LC20 for piston soaks. Remove spark plugs and inject each cylinder with about 3-4 ounces per cylinder. Let soak overnight. Work crankshaft as per below. Siphon any remaining liquid from cylinder before reinstallation of plugs so as to avoid hydrolock. Change oil and filter. Reinstall plugs and kill any remaining mosquitoes. 
Originally Posted By: AVB
I have had good luck with Kreen, I like to fill the cylinders then rock the crankshaft back and forth. I think that it helps to clean the rings better by making them change directions instead of just turning the engine in one direction.
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