Problems worsen for my 1989 Bronco II with a 2.9v6

[Stephen Bowen]

I’m going to preface this by stating that I do a lot of work on a ranger/bronco II forum. I posted below the following, and sadly no one has stepped forward to help me understand this oddball set of issues. Rather then do another write up, I’m going to just cut/paste the other post. I hope someone here can lend me some advice–other then the usual “get another truck, it’s a POS.” Yeah I know it’s a POS. It’s also never left me stranded, and I know every nut and bolt after changing both heads (2.9 ford v6 design flaw. Both heads replaced 4 years ago. World Products redesigned used, 3 transmission later (A4LD auto, very bad from the start, but I finally got a decent one) I’ve let the truck sit for several days, pulled the plugs and spun the engine over. No misting of water/coolant. (wanted to throw that in as I forgot to mention it below)

I’m usually pretty good with repairs. Been having a blast with the wife’s 2001 Beetle (that one is dialed in and running great!)

That being said? Hope my depression over this won’t bring anyone down:

Think I’m coming to the end of my run with this 2.9

No way I can afford to swap to another engine, can’t afford to throw mega bucks at this engine. This one just seems to be slowly going downhill.

Here’s the deal. Maybe someone can help me make sense of this.

Several things in the past I’ve been trying to work out.

First is the odd ‘white’ smoke that appears upon starting the engine. Takes a few minutes after it starts–It slowly goes away after a few minutes. If I drive the truck daily? This white smoke isn’t quite as bad. Leave the truck for a few days? And it’s pretty bad. (edit: It’s not the usual white puffy stuff on a cold morning…this is HEAVY white smoke.

I’ve had a pressure tester on the radiator–It seems to hold pressure and does not look like anything is leaky (other then the heater hose on the water pump has a slight seep)

Start the engine up and remove the radiator cap when the engine is stone cold. It burps out about a cup of anti freeze. It acts like there’s pressure, but there are no bubbles present, nor any exhaust fumes. Didn’t think that much of that test, as I’ve seen that a lot on older cars/trucks. Plus when the cap is off? The coolant doesn’t start spilling out after that first ‘hiccup’ (now let it get to the point the thermostat is getting ready to open? And then it starts to expand and dump a bit. Again, normal from what I’ve seen from other older engines..once the stat opens? Then the level drops a bit and holds.)

When the engine starts up, it acts like it has one or two severe misses. It also seems to bog down badly. Same if you start it and then try to drive before it has a chance to hit “closed loop” (aka, warmed up all the way) It runs like an ignition skip–bogs down… Once it gets to temp? Everything seems to run fair…the engine retains a slight running rough idle, but is responsive. When it shuts off–the engine does so roughly.

When cold the engine also has developed a really bad idle surge. First start it up—and it goes from 1400rpm down to 900….almost like in cycles. Did not find any sign of a vacuum leak (had the same thing happen a few years ago–turned out to be the check valve in the booster and the rubber seal went bad. Replaced both, checked good)

What’s been done so far, and recent replacements:

Installed a new thermostat back to 195 (used to be 180-185) Problem seemed to get worse….but it wouldn’t explain all this stuff happening with a cold engine.

Pulled injector rail and manually cleaned all injectors.

Checked fuel pressure. Holds 32lbs at idle and when line is removed holds 42 lbs. No sign of fuel in the vacuum line.

Compression checked. All cylinders reading 160-170ish. Nice and even.

Spark Plugs checked, rechecked, checked….. All slightly worn–but still in excellent condition. Drivers side front plug was the only one that looked ‘odd’ with a matte black finish on the tip. The rest all had a light shade of gray. No sign of ‘carbon’ or soot. (black matte finish is clearly not ‘flack’ carbon….more like someone took a magic black marker to the plug tip)

Vacuum checks as follows: Upon first starting the engine struggles to hit 18ln. Holds an even 15ish….warms up and stops stumbling and holds 18-19 even. It still acts like it’s being “held back” when taking out for a test drive when cold.

CEL is not on during any of this. I have yet to pull codes, but the CEL has never come on, except during the start up self test bit.

I’ve used a mechanics “ear” and started the engine up and listened to each injector to ensure they are firing. All have a pronounced “tick” as expected.

Did a power balance test–did get shocked by one of the plug wires. When examined while running this plug wire is not arcing to ground–it was the plug wire removal tool that bridged the gap with the pin hole to ground. I mention this in passing, as it was recent with the tool nipping the boot. (It was doing this odd running stuff prior)

Pulled the cap and inspected for carbon tracking…didn’t see anything odd.

Clearly “water” is getting somewhere into the combustion system. I can’t figure out where. The engine seemed to “hydro” lock a few weeks back, it cranked 1/2 a turn and seemed to lock up. It finally started up, did it’s white smoke bit..and ran decent afterwards. I checked and double checked, and can’t see where any coolant is leaking into the system.

As a side bar note. I did have to wonder about about maybe the map sensor? So I had the engine running..and pulled the vacuum line. No sign of any ‘gel’ in the line–and the engine died soon as the line removed. (it would not restart until I reattached the line.)

The TPS was replaced a little while ago–so that part should still be decent. And it does not show any sign of ‘dead spots’ when I’m driving.

As a further note. The converter(s) are fine. This problem has become worse over time–and I did have the muffler off recently to replace it. I had a good look at the converter bed, and it’s good. No sign of any restriction with the exhaust.

At this time I’m pretty well spent. The only other thing I can think of is just saying screw it and replacing the intake manifold gasket–maybe the head gaskets.. I’m just tired of throwing parts at this enigma.

Any ideas or suggestions? Please let me know. I can’t afford the $$ to throw parts at random anymore. Sorry if this seem a bit random, but I went off memory so far and it was hit/miss and I wanted all the details to be good.

S-

Topic

[college man]

Check your timing with a light. Also bring the engine to tdc on #1 cylinder
check that the rotor points to #1 on the distributor and your timing balancer
marks line up. Also check for timing chain slack.

http://www.ehow.com/how_7957739_set-timing-ford-29l.html

http://www.ericthecarguy.com/faq/solving-automotive-performance-issues?start=6#EngineTiming

http://www.ericthecarguy.com/faq/solving-automotive-performance-issues

[EricTheCarGuy]

The misfire and your other symptoms may be the result of a combustion leak into the cooling system as you suspect. You can perform a block test to see if that’s the case. I cover the procedure in this video.

Anytime I confront an engine performance issue with known mechanical problems I start with those first. After they’re repaired I then recheck for the other issues. Most times they’re gone afterward.

Good luck and keep us posted on your progress.

[Stephen Bowen]

Well, regardless I need to buy a new timing light anywho. (the old one had a cord catch the exhaust manifold. talk about a stink)

One of the oddest parts with trying to chase down the white smoke has always been how elusive it is. I had a pressure tester set for 16lbs. Left it attached to the radiator for quite a while (before the tapered rubber seat popped off….lousy design) and the pressure stayed 100% stable.

Next time I chased this one down? I parked the truck for several days and pulled the plugs. All plugs dry. Cranked the engine over expecting to see at least a mist of spray exiting? nadda. All dry as a popcorn fart.

Leave it for several days and you can mosquito fog with the exhaust LOL. But it clears after only 5 minutes and then drives fairly well.

Think it might be time to re-do the intake manifold gasket. It’s a common fault with the 2.9v6 engines to have the coolant runner at the end of the intake start to seep into the intake. (Just wish it would show up!!) I can’t afford a normal block tester kit to check for the exhaust gasses in the coolant. Kinda wish I had the setup that Scanner Danner has with the gas sniffer.

I’ll do both checks and see what’s going on. The engine is quite old and it would be interesting to see what the timing chain is up to….(So I need the timing light anyway) And if I pull the intake? The Disty has to come out and say “Hello” as well. (not the first time I’ve had that pita out. It got replaced with a rebuilt one about a year ago)

I’d rather do the intake gasket first at this point. It’s actually not to expensive for the set, includes all the fixin’s. (Plus the head gaskets are a full blown nightmare. TTY bolts banana: NOT.

I’ll putz around with it more on Sunday. I’m leaving it sit for almost a full week..pull the plugs in the driveway…and see if I get a “shower” LOL.

Eric: I’ll see if I can rent a pressure tester from a different parts house. The expensive ‘kit’ was $215 for the deposit (talk about a major kick in the checkbook…and 5 days later to get the money back) I’m considering slapping it to 16lbs of pressure and leaving it sit for a couple of hours.

S-

[Stephen Bowen]

Well..

Left the old girl sit for several days. Decided before tomorrow I would pull the plugs and once again spin the engine over and see if any coolant was present in the cylinders.

All plugs totally bone dry.

Peeked at the engine fan so I could rotate it in the right direction. (Yeah I know…I should know this LOL. But it was a long day at work) So I grab a belt and start a tuggin’ Pretty easy with the spark plugs all removed.

I get about 3 pulls on it…and the cylinder I thought was suspect? Totally GUSHED out about 2 cups of coolant. Soooooo I found exactly where the problem is. (edit. It’s the front cylinder on the drivers side)

I continued to spin it around a bit more and it’s the only one that is internally steam cleaning my exhaust system.

Next plan of attack would be for me to drive it over to the garage I work out of. (Yeah, I can still drive it. Oddly enough once the cylinder was blown out dry? Ran pretty good LOL)

I’ll pull the intake manifold and inspect the gasket and manifold. From what I’ve gathered, the coolant passage is less then 1/4 of an inch (maybe more like 1/8th of an inch looking at the photos) away from the intake runner. Looks like this finally surfaced.

Thanks all!

S-

[college man]

Glad your making progress. keep us posted. 😉

[Author]

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