[kicker226]

So, my buddy picked up a 03 SE for 500 with a blown motor. We were going to rebuild it for his GF but when we realized what was wrong with the motor, we decided we will fix it and sell it.

On to pictures

oil pan.... nastyyyyyy

Chris cracked the new piston when he was pressing it in.... so we are now waiting for a new one to come in. it probably wont get done until next week when i get back from Hilton NY

 

[st12131]

thats why you heat them up first!

 

[BowerR64]

I think its the design of the intake manifold or the exhaust manifold that is whats blowing these engines.

Either the intake is allowing to much air to flow into one of the ports and its running one of them way to lean or the manifold is over heating one of the cylinders.

I wonder about that EGR setup

 

[mikebontoft]

I dunno.. to be honest my egr was disconnected so it wasn't exhaust heat

 

[BowerR64]

I dunno.. to be honest my egr was disconnected so it wasn't exhaust heat

Well springs can lose their tension after they reach a certin temp.

 

[kicker226]

thats why you heat them up first!

he is the mechanic.... now i wonder if he thought of that wor not.....

I think its the design of the intake manifold or the exhaust manifold that is whats blowing these engines.

Either the intake is allowing to much air to flow into one of the ports and its running one of them way to lean or the manifold is over heating one of the cylinders.

I wonder about that EGR setup

i have no idea. this is the first time ive ever dealt with the SPI motor.... i have a Zetec

 

[jetrinka]

I think its the design of the intake manifold or the exhaust manifold that is whats blowing these engines.

Either the intake is allowing to much air to flow into one of the ports and its running one of them way to lean or the manifold is over heating one of the cylinders.

I wonder about that EGR setup

Wut?

The split port motor uses a feedback ECU (like all modern cars) that monitors post combustion (o2 sensors). If it was running lean it would add fuel just like any other car. It has nothing to do with manifold design..

 

[BowerR64]

Wut?

The split port motor uses a feedback ECU (like all modern cars) that monitors post combustion (o2 sensors). If it was running lean it would add fuel just like any other car. It has nothing to do with manifold design..

wut? i thought the sensors just monitor the over all not for each cylinder?

On my car its in the exhaust manifold right in the center so how can it tell which cylinder is doing what?

So what your saying if i have a bad injector that is not spraying as evenly as the other three i can pinpoint exactly which one it is without just guessing and swapping them one at a time?

There is a design flaw somewhere that is causing the same valve on every one of these motors to drop. They overlooked it and decided not to correct it but to just change the whole engine.

 

[kicker226]

There is a design flaw somewhere that is causing the same valve on every one of these motors to drop. They overlooked it and decided not to correct it but to just change the whole engine.

youre serious when you say that? i talked to chris, and he said swe might throw another head on it, fix the piston, and tell his girlfriend to drive it.

 

[jetrinka]

wut? i thought the sensors just monitor the over all not for each cylinder?

On my car its in the exhaust manifold right in the center so how can it tell which cylinder is doing what?

So what your saying if i have a bad injector that is not spraying as evenly as the other three i can pinpoint exactly which one it is without just guessing and swapping them one at a time?

There is a design flaw somewhere that is causing the same valve on every one of these motors to drop. They overlooked it and decided not to correct it but to just change the whole engine.

If there was a problem this severe that one cylinder was being destroyed by some hideous difference from the other 3, the engine would run extremely poorly. It would feel like a really bad misfire.

 

[BowerR64]

youre serious when you say that? i talked to chris, and he said swe might throw another head on it, fix the piston, and tell his girlfriend to drive it.

Its just my opinion. Ive been on this board for a while and i looked at buying another used focus but i always seen the SPI cars forsale and all of them had blown engines.

So i read around here and i keep reading the same issues with others on this forum and dropped valves over and over and over and they are always the same one.

If it was just a faulty valve part, or a faulty spring it wouldnt just happen on the same cylinder.

If there was a problem this severe that one cylinder was being destroyed by some hideous difference from the other 3, the engine would run extremely poorly. It would feel like a really bad misfire.

But see thats just it, you might not feel it. If it was running lean enough you could feel it they wouldnt last 100k THEN blow. Im talking about a slight flaw that causes that cylinder to run slightly hotter then all the others causing it to slowly burn up prematurely till it finally gives out.

Its obvious there is a problem with the head, it could be cooling issues also i guess.

 

[jetrinka]

Its a valve seat problem. They just aren't of a very good design and eventually loosen up from the head and drop out. Its a bad designed valve seat and thats all.

 

[kicker226]

Its just my opinion. Ive been on this board for a while and i looked at buying another used focus but i always seen the SPI cars forsale and all of them had blown engines.

So i read around here and i keep reading the same issues with others on this forum and dropped valves over and over and over and they are always the same one.

If it was just a faulty valve part, or a faulty spring it wouldnt just happen on the same cylinder.


But see thats just it, you might not feel it. If it was running lean enough you could feel it they wouldnt last 100k THEN blow. Im talking about a slight flaw that causes that cylinder to run slightly hotter then all the others causing it to slowly burn up prematurely till it finally gives out.

Its obvious there is a problem with the head, it could be cooling issues also i guess.

i told him we should just forget about SPI and throw a zetec in it, but he doesnt waznt to change the ECU and the wiring harness

Its a valve seat problem. They just aren't of a very good design and eventually loosen up from the head and drop out. Its a bad designed valve seat and thats all.

maybe im just new to all of this, but what do you mean when you keep saying valve seat, wouldnt it be something wrong with the piston.... the bottom of the piston shattered into a million pieces.... like fell off of the connecting rod and everything

 

[mikebontoft]

valve seats are the metal rings that the valves seal to. because of the different properties (they are dissimilar metals) the head and seat heat/cool and expand/shrink at different rates. It gets bad enough that they eventually work their way out of the head and start tapping around. This is the poor design as mentioned above by jetrinka.

Think of a washer around a bolt (washer=seat, bolt=valve), put though a piece of metal from the bottom up (as the head, also with a recess just big enough to fit the washer) with a nut on the other end (spring/guide assembly. to keep the valve from falling into the cylinder).

It can move up and down all it wants to, and the washer can't fall out. When you pull it up, the washer is stuck in place. This is where the ticking comes from and why there isn't usually a misfire at first, save for an occasional one.

Now think of the washer a having been cut on each side. what does it do? it falls apart. down into the cylinder. Now you have two (or more, I can't say for sure) pieces of metal in an engine with very tight tolerances, with nowhere to go as the rotating assembly continues to spin. These pieces are a bit harder than the aluminum head and piston so as they are compressed, chopped, into pieces they put gashes into whatever they hit except for the cylinder walls because of the block's composition of iron.

If you're wondering why all those metal pieces ended up in the other cylinders, there are two possibilities. Some get pushed through the non-sealing intake valve back into the intake manifold, and some of it (I will have to check my EGR because I'm just now thinking of this) gets pushed out through the exhaust valve and possibly into the EGR back into the intake manifold. Then it gets spread around everywhere.

There are some extreme cases I've heard of where the damage to the failed cylinder is enough to blow a hole in the block. I haven't actually seen it but it's what I heard [dunno]. The bottom of your piston breaking up could be an odd case, but once again I haven't pulled my oil pan yet so maybe it HAS happened to mine. I've never been aware of that happening though.

Also, the rod is usually bent when these drop a seat, and the cylinder wall is usually fine after a light honing.

this is what the head should look like since I didn't see a picture of yours.

 

[kicker226]

thanks. im understanding it a little better. i dont have a picture of the bottom on the head, just the top. the rod actually looked fine. i think we are going back down this week to finish it up. hopefully....