Made an un-nerving discovery today

[ForcedFirebird]

Started yesterday when my truck started mis-firing. I think to myself "odd, the plugs/wires usually last way longer than this". When I get stopped at my destination, apply the praking brake and leave the the truck in gear (auto) to emphasize the miss. Start pulling plug wires one at a time, and they all are firing nicely. Another thought "must be plugs", so I go order a set of plugs and wires to take care of it this morning, and here's what I find...



Looks normal, right?


Look closer...



Touched the tip of the plug to my toung, an it's definately coolant . Just had the upper radiator hose off about a month or two ago, and the coolant was nice and green, but when the cap was opened today, it's a nasty brown (frowned again )

This truck has never been overheated, although yesterday the temp shot above normal for about 30sec, then went back to normal- aluminum heads. I'm guessing this is because the coolant was getting low, but thought maybe the t-stat stuck for a moment. It has 190,000 miles on it now, and am finally going to have to do a top end overhaul. It's going to be a pain because it's a modular 4.6 with OHC's, and 1/2 the engine is stuffed under the cowl (kind of like LSx cars).

Looks like the Firebird isn't going to have much progress this week.

[IsaacHayes]

Darn. It must have got jealous and wanted to steal your attention.

[ForcedFirebird]

Darn. It must have got jealous and wanted to steal your attention.

Confirmed. After the plug change and adding a bit of coolant, it started right up. Then let it run for a couple mins, and shut it down. When re-started, it puffed smoke There is a little bit of foam in the oil, so the coolant and oil systems mixed, and it had a faint tapping from down low. Now the bearings will have to be inspected, hopefully the oil is just thin from the water, and the bottom will survive.

AAA will get a call tomorrow to get it to the shop, and I'll start digging in.

Funny, the top end gasket kit from FelPro is the same as the GM 3500 kit I just bought.

Truck has been good to me. Tranny rebuild at 113k miles, then again at 160k (guy used cheap sprag and it broke again, but he waranteed it ), radiator went at 150k miles, the alternator at 175k. It's now got just a hair under 190k, and this is the first major thing to be done on the motor. Oil, plugs, wires etc have been changed faithfully, so my fingers are crossed that the bottom is good. Even if the bearings need changing and it can be done from through the pan, that won't be too bad.

[sharkey]

what year and model is it (150, 250 or 350)??? if its a 150, get ready to do the diff soon. i did 2 diff jobs on f150s this past week. both took out the spider gears (they are made of real weak metal), one just needed a new carrier and bearings, the other needed the ring and pinion, carrier, bearing kit, and both axles, basicly everything but the housing basicly.

[ForcedFirebird]

what year and model is it (150, 250 or 350)??? if its a 150, get ready to do the diff soon. i did 2 diff jobs on f150s this past week. both took out the spider gears (they are made of real weak metal), one just needed a new carrier and bearings, the other needed the ring and pinion, carrier, bearing kit, and both axles, basicly everything but the housing basicly.

150, and the rear has been sweating for a bit of time now. Since it is a work truck (and obviously sees lots of miles), there is going to be some overhauling while it's down, I'm glad you reminded me about the third member

Just sucks. Like I said the maintainance was kept up, and it never overheated, seems odd for a head gasket failure so soon.

[ForcedFirebird]

Since this is my company truck, I really don't like working on it if it can be avoided (spare time is for my car, lol). I called my good friend who owns a repair shop, just in case it was reasonable enough just to drop it off, and I wouldn't have to let any jobs sit (I'm a GC). He won't even do the head gaskets with that many miloes on the lower end (190k), and suggested we put a used motor in.

The cheapest used motor I could find had 150k miles and was $1000, and the lowest milles I could find was 70k and they wanted $1700! WTF are these motors that good?

Decided to give egay a shot for the hell of it, and there just so happens a person is selling a crate motor never installed for $1500, pick-up only and is 1.5 hrs away. Something's wrong my luck is never this good...

http://cgi.ebay.com/ebaymotors/ws/eB...link:middle:us

The rest of the truck is pretty solid with the exception of the rear sweating and the sprag is worn again in the tranny, but it's not feaseable to buy another truck right now and this motor should last another 200k providing I do the same maintainance schedule I used on the last one.

The old motor will then get rebuilt and judging by the prices, should pay for this motor and then some

Going to take off my flywheel cover now to make sure I have an 8 bolt crank *crosses fingers*

[sharkey]

your not going ot be able to see the flex plate to crank bolts with just the cover off, your going ot need to get the motor or tranny out for that.

and yea, those motors are pretty horrible. had a 2000f150 towed into our shop making a bad noise, customer thought it was the tranny, turns out it had thrown a rod. turns out the cheapest we could find a motor was $2100 with less than 100k km on it, the biggest problem was there were only 3 around.

[ForcedFirebird]

your not going ot be able to see the flex plate to crank bolts with just the cover off, your going ot need to get the motor or tranny out for that.

and yea, those motors are pretty horrible. had a 2000f150 towed into our shop making a bad noise, customer thought it was the tranny, turns out it had thrown a rod. turns out the cheapest we could find a motor was $2100 with less than 100k km on it, the biggest problem was there were only 3 around.

Motors don't seem horrible as far as reliability, though. Mine has been beat to crap for almost 200k mi. Man, what did they do to throw a rod? The rods are forged, and will bend before breaking. Just a bad bearing, then?



After some research, it seems the manifold gasket goes out, just like the 660's. There is no water in the oil, and I'm going to start pulling parts to see. If that's the case - wonderful, otherwise that crate motor will have a bid on it

[sharkey]

likley a spun bearing caused it to break a rod.

[ForcedFirebird]

It was a LIM! Actually the way this intake is designed, best to call it a manifold to head gasket, because the plenum is on the bottom of the manifold and that seal didn't have to be comprimised. The design is pretty cool on these engines with the variable intake runners.

Can you guess where the leak was? (BTW Ford also has the infamous orange coolant)...







Look at the intake design...

[IsaacHayes]

Good news. Clean it up and should be good to go. Are you still gonna check the bearings or do you think the noise was it just missfiring?

[ForcedFirebird]

Good news. Clean it up and should be good to go. Are you still gonna check the bearings or do you think the noise was it just missfiring?

I'm thinking the noise was detonation from having slight water in the chamber. You are the only one who picked that up, lol.

If the noise is still there, I read up on the modular motors today, and the oil pan and caps can be pulled with the motor in

[ForcedFirebird]

It lives!

I think the knocking noise may have been a lack of oil that was causing the knock. this thing rattles like a can full of bolts when oil is low. Realized when I went to put the used oil back in the containers just how low it was. It is burning a bit of oil, and the valve seals are suspect.

Runs beautiful! It hasn't idled this good in a while - I actually thought it had stalled at the light during a test drive, but was just running that smooth. The RPM's at idle also are much lower/smoother could have been sucking some air - or - the EGR that got replaced while it was apart (no more "check engine" ). Makes me wonder how long it was leaking.

[IsaacHayes]

Good deal! Turned out better than you thought.

I know what you mean about running smooth and you think the engine dies. Mine still freaks me out on the high way because I'm expecting it to shift out of OD, but it doesn't it just pulls. Before I did the intake swap it would have no pull in OD going up hills and would always kick down. Now the TC stays locked and it pulls, you don't feel anything and you think "oh shit the car just died"