And...concerning the coolant, how much loss is attributable to evap?
I changed the coolant 1 yr. 3 mos. ago, driven 15K since, haven't added any. Looking at the bottle, it's down maybe 1/4" from the full mark. But then I'm not sure if it has lost coolant or if I didn't fill it exactly full. Wasn't really trippin' on that at the time. I do know that it is not using a noticable amount of coolant tho.

 

The amount of coolant the motor was using was so negligible I never dreamed it would have a cracked head... only when this "old timer" I know who was a mechanic for years at the local ford told me to do the "loosen the radiator cap" test... pressure testing didn't show any leak, no bubbles in the coolant... the first plug to go bad had a cracked ceramic around the electrode when I changed them. Just figured it was a fluke thing since they looked to be original (had the different part #'s on each bank), they were replaced with SP500's (Ford's new part replacement #)... all seemed fine for 5-6 mths, then the slight miss on cold startup, followed by severe misfire couple weeks after that. The plug was rather wet, somewhat fouled looking by this time. Replaced it with another new plug, ran fine for a month or so... this time I pulled the plug as soon as it started the miss on cold startup... it looked fine at this point. The 4.0 ohv is a very easy motor to tear down and replace heads on... its just a time consuming job, and I put in all new lifters, pushrods, etc while I was at it since it had just over 100,000 miles on her and plan on keeping her a few more years. I am happy so far with the results, runs like a new motor now, no slight lifter peck, etc. If you pull the heads and one or more pistons look clean and the others have carbon on them , you definitely have been getting coolant into the cylinder somehow.

 

The problem with doing nothing is that, a cracked head or bad gasket allows for coolant (i.e., sodium and potassium) to mix in with the motor oil. Even the slightest amount of coolant in the oil can cause increased bearing wear. Referencing again the UOA I had done on my 4.0l (Ranger Used Oil Analysis), take note of the high iron content (46) compared to the universal average (18). Doesn't sound like a real big deal, but over a long period of time, who knows what will happen. Maybe a spun bearing at some point?

 

Some good trouble shooting ideas on trying to see if you have a cracked head, or head gasket problem, with a leak down/blow down, sniffer test, ect.

The exhaust bubbles in the coolant, whether seen, or sniffed, is a good clue & a easy to do test.

If the coolant level is slowly droping, with no external signs, that would be a indication something is amiss, so maybe consider adding a florescent dye to the coolant, run it for a week or so, then pull the #4 spark plug & shine a black light on it & see if any dye shows up, it'll glow a bright yellow/green.

As Rockledge has said, a UOA will show any coolant in the lube & if so, it won't be a good sign, nor a good idea to run the engine this way.

If you find it's likely a coolant leak into #4 cyl, but are still really adamant about not tearing into the engine, to find out & fix whats going on, then maybe consider trying a "block sealant", as that might be better than doing nothing.

I remember over on the Motorweek forum reading about one of the GM guys using a GM product called, "Cadallic Pills", to stop the leaks in his Northstar engine. He said if you went to a Caddy Dealers parts counter & asked for Cadallic Pills, the parts man would know just what you needed!!!! lol

Too bad you don't have the old plugs, as they could be checked on a "spark machine" to find out if a ceramic is cracked. But then installing it into another cylinder, to see if the miss code follows, is sorta a poor man's spark tester!!!!

 

I agree that coolant contamination, if occurring, ultimately can cause major bottom end problems.
It was mentioned that on one engine, the plug in question was wet, mine was dry with no deposits.
I mailed off the UOA today, so we will see.
Even if the UOA is negative, I'm still gonna go forward with the other troubleshooting.
Like I said, I really don't want to tear the top end down for maybe nothing, without knowing for sure.
The motor runs perfect right now, uses no oil. Emissions output is comparable to what a new truck would do. And if I tear it down and then get into serious top end work, I might as well think about doing the whole motor. With 140K on the clock, a top end job may blow out the bottom end. Seen that happen before, fortunately not to me tho.
Great brainstorming on this topic tho. Originally, I thought maybe there was some trick fix for this issue, if it was a common one.
Gonna have to put in the work on the troubleshooting and go thru it step by step.
The head problem is an interesting angle tho, I would have focused more on an ign problem.
Stay tuned, this ain't over yet.
Anybody has their 2 cents to add, have at it.
Thanks y'all for your interest in this. We'll see what we can learn.

 

If the UOA comes back showing coolant in the oil, and if it's not practical for you to open up the motor at this time, then I agree with paw paw, you might consider using some heavy duty Bar's Leak. I'm usually not in favor of that kind of "quick fix" but if it means prolonging the life of your engine, then it 's worth a shot. Some people swear by the stuff.

 

I've had this problem going on a year now. I've tried replacing the plugs and wires, replaced bad o2 sensors, cleaned the MAF and changed the air filter, had the fuel trim checked (came back normal). It appears the last time I changed plugs the 1st cyl had oil on the threads while the others didn't. I haven't had a CEL since getting the o2's changed a few weeks ago. On cold start, the truck shakes a little bit. If I put it in Drive, it shakes bad. If I put it in reverse gear, it shakes REALLY bad. I also have the "coolant sipping" problem. My mechanic said to bring it in for a cold start diagnostic for $70. He would check for an intake manifold leak. Since the truck has 116K, all of the above mentioned things are just normal maintenance. I'm going to try the trick listed above to check for a cracked block. I just thought I'd post this b/c I've been following for a while, hoping to catch a break in the mystery. This board is awesome!

 

Rockledge-
Ya, I'm not one to use stop leak either. I've had to go behind that stuff to do repairs that others should have done but didn't, and opted for the stop leak attempt fix instead. What a mess in the cooling system! And it didn't stop the leaks either.
Well, as you all know, troubleshooting rule #1 is, make no assumptions. Next step is, we'll just have to wait for the UOA. If it's positive for coolant, then I would say most likely it's the head, or head (or IM) gasket. A cracked block could also yield the same result, but highly unlikely in this case, as the truck has not been exposed to any conditions that would typically cause a cracked block. In any case, if the positive result is the scenario, I will have to make a decision as to my course of action to take.
If it's negative, a sniffer & leak down should further rule out any gasket/ head problems. The way I see it, these tests may also be necessary anyways, even if the UOA is negative. This is because a crack in the head may or may not cause coolant contamination of the oil, depending exactly on where the crack is.
I would prefer to fix it right or not at all tho. So let's see what Blackstone says.
If we can solve this problem, we will all be more knowledgeable for it.

 

You say that the #4 plug had no deposits & was clean, so was it "cleaner' than the others????

If so, it may have been "steam cleaned", so if the UOA comes back positive, the extra clean #4 plug might serve as corroboration of a coolant leak.

As to the question about how coolant could kill a plug & it not having any outward signs, maybe it's being thermal shocked by the colant leak & the inside ceramic is micro-cracking.
Sure would be nice to have at least one of the old plugs for testing.

Anyway you'll soon have the UOA feedback to see where that leads.

So keep us posted, this is getting more interesting than one of those TV Soaps!!!! lol

 

I should clarify and say that, by reading the plug, it was normal. Not fouled, slight tanning of the insulator, no carbon/ oil deposits. Basically, it looked as a normal plug should, keeping in mind it only had 4K miles on it, give or take. I wouldn't expect a plug to look too used at 4K, esp if the engine is running normally (good gas, fuel trim within parameters, no valve guide or ring leakage, correct heat range, no detonation, etc.). It didn't appear to be "cleaned" in any aspect. Also, I was thinking that maybe there might be coolant deposits (minerals) on the plug, if that were the case.
As far as comparing #4 to the other plugs, I don't believe that would be conclusive, as the other plugs now have close to 40K on them. I would expect the #4 plug to look newer and cleaner than the others.
The "failure" interval is pretty consistent also. It is possible tho that the root cause could be causing plug failure at regular intervals, but I would expect more deviation in failure intervals.
I will save the next plug for further testing and detailed inspection. The engine has been good at providing me #4 plugs to check on a regular basis, so it seems.
Next time I pull the plug, I'll see if I can see into the combustion chamber to see the piston crown, to see if it's clean.
I know that the plug failures are merely symtomatic, not the causative factor in this problem. Odds of getting three bad plugs into the same cylinder are pretty miniscule.
l will be interested to see the results of the UOA.

A side note- when you send in your UOAs, you may want to think about using USPS. Blackstone said in their brochure that postage was about $2 by USPS. I sent it UPS instead, and shipping with an envelope supplied by them was almost $10. I was already at UPS, and I didn't feel like going to the post office and then waiting there again, so I paid it. But be aware of this if you are planning on sending a sample to Blackstone.

 

Well, I got the UOA...I would post the analysis, but I don't know how.
Rockledge, you posted yours, how did you do that? Scan it in or something?I'm kinda stupid when it comes to computers.
Basically, there is a little antifreeze, .19%.
In PPM:
Boron 154
Sodium 94
Potassium 1
Blackstone said that, for now, they thought I could just monitor and change oil at my present intervals, 3-3.5 K.
I'm thinking probably a small leak at the IM gasket. Slight coolant leakdown into intake port for #4. Then at startup, enters cyl then burns off.
A sniffer/ leak down should be able to rule out a head/ head gasket problem, methinks, esp if it's a leak on the IM side of things.
I'll check the torques on the IM next to see if any bolts are loose.
So, what about the plug issue, would such a small amount of coolant cause plug failure?
What say you on this?
If you'd like to see the report, tell me how to post. Thanks.

 

Radio check...

 

BUMP, so how are things going B A dawg????

 

#4 plug, is that the center plug on the drivers side of the engine? When my son was given the Mazda that I'm driving today he told me that it had either a blown headgasket or a cracked head. I didn't see or hear the truck run since it was 500 miles away. So I told him to try this product Bar's Leaks Head Gasket Repair . Since the truck itself was free what did I have to lose? He followed the instructions to a tee and when I got the truck home and drained the water out of the cooling system it was clear enough to drink. Doing that, putting an exhaust system on it and some money for delivery to Mackinaw City from Grand Rapids and I was out $300.00. I ran the truck all through a Michigan U.P. winter with no problems other than what was caused by a bad MAF sensor. The following spring I gave the truck a full tuneup and my drivers side center plug was so fouled that I'm suprised that it could even fire. It was only Just begining to miss. After the tuneup the plug after 15,000mi. still looks fine. This product can [and did in my circumstance] work. I'm not some company shill, just speaking from a single time experience, so ymmv.

 

Well B A dawg, how is it going with your regular failing #4 spark plug & it's failure analisis????

We've recently had another thread with a similiar problem.