Dang it, I broke it. COMPRESSION CHECK 08/07

I admittedly drive my Dakota with a heavy foot, but, never literally foot to the floor screaming high RPM's....

In a moment of frustration/panic, I wound the engine pretty tight last week.

Now it smokes every time I start it.

Too little time and too hot outside to dig in and diagnose it right now. Aside from the smoky starts, truck feels no different. But, it is using oil now.

I'm thinking of buying a long block for it, but, with 166K on everything else, what kind of can of worms would I be opening?

Truck is rust free (not dent free though) and aside from the AC not working, has been a good little truck in the year and a half I've owned it.

Truck has the V6 and I would probably keep it.

Just thinking out loud here.

What would you do?

Lower pan on intake been done on it yet?

I would keep it and build a fresh V6 for it. The truck does not owe you anything and whatever you get to replace it will have its own host of gremlins to be sorted.

I have thought several times that I should be selling my '87 and get a newer truck. I have seen a lot of appealing Dodges on CL and they would be perfect for towing a car trailer with the Ramcharger. But I don't need it yet and I also don't have payments either. The '87 runs very well, gas is cheap now, I have a new canopy on it and my dogs are comfortable and secure in it.

BTW 166K is not a lot of miles for a truck.

Texas without AC? You are tougher than I am .....LOL

One of the first things I did. I used the Hughes kit.

No A/C in this hasn't been too bad. My wagon has no A/C and that was BRUTAL!

Time to swap in a 318 or 360. More power and no worse on fuel. Go to to the salvage yard and find a low mile motor and stick it in there.

If I go with the V8, do I need to swap the trans too?

Then there's the matter of wiring and computer.

I looked underhood one day and thought "Hmmmm... a modern Hemi would fit".....but reality is that would be WAY beyond my budget.

Or would it?

Depends mostly on wether its new enough to have electronic governor. that showed up in 96 or 97 I believe.

The trans will bolt right up to a v-8. The motor mounts, accessories and exhaust bolt on. You will need a v-8 PCM and possibly a harness. I was cheap and used the existing
V-6 harness when I did mine. Just had to add 2 injector driver wires to make it work.

let it go---buy another with a v8......

I'd drive it til it drops, if it all of a sudden started smoking I'd guess it's probably the plenum gasket, it's worth a check. The chance of the engine being hurt would be pretty minimal I'd guess

I guess I'd be disappointed if it was the plenum gasket since I replaced it with the kit from Hughes.

When I did the gasket swap, I was to find that the manifold was basically just resting on the engine. NONE of the intake manifold bolts required a wrench to remove, ALL were loose and removed by hand. Once all the bolts were removed, the manifold simply lifted off. There was no work required to break a seal. Aside from a slightly high idle (and evap controls that didn't work) the truck seemed to run fine.

He's right.

There's lots around, they are dirt cheap and the miles are low. Not only that, but I think you will get your money back at re-sale time: you'll have the only 360 Dakota in the classifieds and people will want it!

Oh, and of course I never forgot: you shoulda dumped it and bought that white truck.................like I told ya to.

Hee hee, just kidding! Shaddup right?

But, seriously, earlier when I asked about if I need to swap the transmission, I meant would it handle the added power of a V8?

I think you're okay. If the weakest one you have is the 904 based one (42 or 44RH/RE) it should'nt be an issue. Actually, better than the 727 based power-sucking turds (46RE/RH).

Around here those trucks probably sell for less then $2,000. I would just find another truck with a V8 this time. I wouldn`t dump any money into it if it were me.

You can buy a LOT of oil for that same money. Drive it until it's dead (and that that won't be for a LONG time!)

I guess the question is, how much oil is it going through?
That would be the deciding factor. Might be a good time to run a compression test to see if you broke rings or piston ring lands. If the compression test shows OK, you probably blew out the valve seals or the bottom intake gasket.

I over revved the 3.9 in my coupe when I was out playing one day. Even after that, it ran nearly a full year before I grew concerned enough I replaced it. That motor had a pretty sorted history to begin with, and 149K miles on it. I replaced it with another 3.9 (I bought a wrecked truck with a good motor for cheap). That replacement used motor uses a quart of oil about every 1,000 miles when driving around town (even nearly dead, the original motor didn't use oil).
The "new" motor has 118K miles and has had a timing belt replaced.

The truck I bought (for then scrap price, $275) has nearly paid for itself from parts I've sold off, I'm keeping it around in case I need something else, too bad the frame was bent so badly.

Even with a nearly free replacement motor, I have $300-$400 in stuff I've replaced with the motor (the while I'm here syndrome).

I'd run your current motor until it shows signs that concern you. That may be a very long time. A running driving Dakota (of that era) that moves down the road (even with a smoking motor) will bring $1,000 here, parts trucks still bring $500. Run it until it dies, then sell it to someone building an old car or truck. Gene

I don't see a lot of smoke, but,admittedly its hard to watch the tailpipe all the time.

Usually it uses about half a quart between oil changes (3500-4000 miles), its gone down half a quart in about 200 miles since this happened.

And today I (briefly) heard what sounded like piston slap? Not 100% sure, but, it was definitely a sound I haven't heard before.

Prices on Dakotas around here vary widely (by huge margins), no rhyme or reason. It's VERY rare to see one below $800 no matter how trashed it is.

I almost scored another '93 for cheap last year, but the owner wouldn't budge on the price. The truck ran good but had a blown trans, they were asking $650, I had $500 cash and honestly couldn't go higher at the time. They junked the truck instead. I guess Pick-A-Part gave them more than I could.

My powerwagon was exactly like that... big puff of smoke on start up. Pull the valve covers and see if the seals are even there. Some valve seals and valve cover gaskets are cheap. I'd go with poorboys suggestion with a compression test first, just to make sure the cylinders are good.

That is the first thing you should do (1) Compression test - dry (2) Compression test - wet (2 squirts of oil in each cylinder before testing) this will determine good rings or bad, if no change and still big variation in numbers then you have a valve sealing issue. Testing is cheap and will prove a lot.

I'd say you shatter a ring or two, when I did that it started using oil and smoked...

Yea, I did that in my younger days. Bought a nice big block car from a little old lady, then my young butt started hot rodding it. In very short order it started smoking. My boss informed me that a ridge forms at the top of the cylinder above the top ring travel. When you dramatically increase engine rpm over what it usually ran, the rings travel up the cylinder walls a couple thousands and the rings hit that ridge and break the rings, or the pistons around the rings. OOPS!

The more something costs you, the better you remember the lesson. Gene

I won't be able to diagnose it until this weekend, but, I noticed something different today.....

The PCV valve doesn't buzz anymore.

Back in April I posted here asking why it would buzz, most people felt it was 'normal'.

Pulled the PCV valve out tonite, its not full of oil, and still has strong vacuum.



Saturday can't get here soon enough......

How much blowby does it have with the PCV valve pulled?

OK, here we go. My gauge reads in 5 lbs increments, so slight differences are hard to put an exact number to.

Cyl 1: 160
Cyl 3: 155
Cyl 5: 155

Cyl 2: 160
Cyl 4: 165 (checked this one twice dry, same reading)
Cyl 6: 155

A squirt of oil had minimal affect.

Here's a pic of the plugs:



Nothing looks 'wrong'.

One thing I did notice is I smelled gas quite a bit on the plugs, even though the truck had been sitting for about 10 hrs without being started.

Same thing when I was doing the tests, I could smell gas. I had the fuel pump relay unplugged, the coil (power) wire unplugged, and the throttle body held open during the tests.

It smelled enough that my wife asked if I had spilled gas.

Smelling the oil, it just smelled 'used', no strong gas smell.

I'm leaning towards it being the valve stem seal(s), but, the fuel smell has me concerned.

Ideas?

Those are good numbers and nice looking plugs. Have you looked into the intake to see if there's oil in the bottom of the plenum? Also see how much vacum it pulls at idle, a blown plenum gasket should show low vacum

I couldn't find my vacuum gauge, so I have no readings.

I just have this unscientific video....

PCV vacuum

Oh, and the 'buzz' from the PCV returned yesterday.

One more video showing the V6 at idle... idling V6 zzzzzz

Like I said previously, it runs no different. It just smokes at first fire and uses oil now.

Still sounds like valve stem seals or intake.

I agree. Just to dang hot out right now to dig in.

It takes a lot of extra oil usage to add up to the cost of most repairs. Think maybe I would give it a fresh oil & filter change, and track exactly how much oil it is actually using. Back in the old days, Chrysler said a quart in 500 miles was acceptable, even in a new motor! From my perspective, a quart in 1,000 miles is borderline excessive.

When you have to add oil between gas fill ups, I believe the oil consumption has exceeded excessive, and its time to do something.

Most of my higher mileage Mopar motors have given a puff of smoke when they start. At least I know they are getting upper cylinder lubrication. Gene

At start up, SMOKE or STEAM?

As I said earlier, it takes MANY $3.00 quarts of oil to equal a quality repair to rid the SMOKE. Even at a qt every 1000 miles, and say $300.00 to fix seal, that's 100,000 miles of driving. Just sayin'...

Sounds exactly like valve stem seals. Probably not to hard of a job to do this fall or winter.

Oil consumption.....

It's definitely using more at freeway speeds.

Took the truck down to West Beach (Galveston) yesterday. Checked the oil before leaving, dead on the fill line.

I drove approx. 90 miles round trip, 30 of which were slower 'in town' speeds.

Checked oil a few hrs after I got home, it was down to the add line.

Yes, I've had a few cars that burned WAY more oil, but, to go to this much use from less than half a qt in 3500+ miles is a bit of a .

On a side note, I didn't have a full tank of gas so I couldn't calculate the MPG, but, the truck used about a 1/4 tank to cover those 90 miles.

You hear any pinging on the highway cruise?

With the compression numbers you have, I think I would be looking at an intake gasket failure, either the bottom gasket, or the actual intake gaskets. Its got to be pulling oil into the combustion process, the compression numbers you have means its probably not coming by the rings, and that is a lot of oil coming through the valve guides, even if the seals are nearly gone.
Two other possibilities come to mind.
1) Somehow the oil returns to the pan got partly plugged up and the oil is sitting up in the valve covers.
2) Oil is running out on the ground from someplace, Oil sending unit maybe? Gene

I don't hear any pinging at hwy speed, or any speed for that matter....

There's no puddles under the truck or on the engine. It just looks like a typical high mileage piece, no excessive oil on the engine anywhere.



I'm just gonna stick close to home with it until this heat breaks and I can dig into it.

Thanks everyone.

Like WO23 asked " Have you looked into the intake to see if there's oil in the bottom of the plenum?"

I took a look Sunday, it doesn't look as clean as it did, but it doesn't look wet either.

Oh, and here's a shot of where I always park my truck at home.....not a drop on the ground.

Its been ...two months since I thought I broke my Dakota.

The summer heat finally ended, but now life (re:work) keeps getting in the way, so I've done nothing to it except drive it.

Where I'm frustrated/confused is that once the extreme summer temps quit, oil consumption went way down, and now that more fall like temps have finally arrived, oil consumption is back to what it was originally.



I really like this little truck, but, my lack of time (and knowledge) to diagnose all its little quirks, may push me in a direction I didn't want to go.

One other quirk that seems temp related is an occasional dead miss at idle (sitting at a light with my foot on the brake). Only happens when its HOT out. Lean miss?

And as of late, I've noticed it runs so much better/stronger, when its 80 or cooler out and it has half a tank (or less) of gas. Hard to explain, but, its not a weight difference thing. Don't laugh at my example, but, when its really hot out, the truck will just kinda mosey up to speed if you gun it. Half a tank and temps 80 or less, the in dash cup holder will slide open, and it'll chirp second. I know its not uncommon for cars to run better in cooler temps, but, this seems a bit extreme, especially for a computer controlled one.

Like I've said, I'm just frustrated right now.

With heat related issues, I wonder if there is a problem with the Evac system dumping fuel from the carbon canister when its not suppose to. I'm not sure how the system works on the year of your truck, but one would think there would be more fuel evaporating with the heat, and that could overload something in the system? Gene