[RESOLVED] Smoking and Backfiring After Compression/Leak Down Tests

[snowborder714]

My brother and I were tuning my car yesterday evening. We kept getting knock before boost so we decided to call it quits for the night. We stopped in a parking lot and noticed the CEL was on. I brought up DSMlink, but it wasn't throwing a code. About 2 minutes down the road, I finally got it to stream (it's a really old laptop and works slow) and noticed the coolant temps were around 250*, so we immediately stopped the car and shut it off. We let it cool down over time and with the aid of a box fan. We got it home, not seeing the coolant temps above 190*. It drove fine with no problems on the way home. When we worked on it today, we found that the fuse and fuse holder for the fans had melted! So we replaced everything and got it running correctly. It was still driving fine.

Then tonight we did a compression (both dry and wet) and leak down test. Here were the results:

Compression Dry Test
140-135-135-138

Compression Wet Test
200-195-195-199

Leak Down Test
All cylinders were 16% with leaks heard at oil cap and dip stick


I also ended up breaking one of my NGK spark plug wires (at the coil pack) so I replaced them with another brand new set of NGK's my brother had. I started it up using the firing order 3-2-1-4 (on the coil pack), but it didn't sound right and started smoking like crazy. I shut it off quickly and popped the hood. After the smoke cleared, my brother noticed a good bit of oil on the front metal timing belt cover (goes under the upper cover) and around the exhaust manifold. The top right stud for the exhaust manifold to head is broken off in the head. We removed all the spark plugs and cranked it over with the gas pedal down to cut fuel (DSMlink feature). We took it around the block and it would not get into boost and it felt like a tractor. It was also backfiring a lot and sounded weird. We check the timing - the cam gears line up fine, the crank looks to be good (we didn't remove much to look at it though), and we didn't check the oil pump mark. All fluid levels are fine and base timing is correct. We hadn't changed any settings in DSMlink since it was running fine. The only thing I did notice while it was running like crap is that the g/rev was really high - should be .28 but was .52 or so.

Could the leak down test possibly have freed up a big exhaust leak? Any other ideas as to what could be wrong?

A log is attached from the run around the block when it was acting up.

 

[Freerevving]

I think your rings haven't broke in yet... not sure about the knock

 

[snowborder714]

This is the engine that came with the car. I have not touched the internals at all. It has an unknown amount of miles on it. I've put almost exactly 7k miles on it since I purchased it almost 2 years ago.

 

[livedsm4g63]

what kind of psi did you use for the leakdown test? shop air?

 

[turbosax2]

We used a small air compressor (5 gallon I think) set at 60 psi.

 

[snowborder714]

Since I have a 1g engine/coil pack I use 1g NGK wires. The wires are labeled near the coil pack for which cylinder they correspond to. Stupid me assumed that cylinder 4's wire would be the longest, but alas, cylinder 3 has the longest wire and cylinder 4 is the second longest. I put the wire marked 3 in cylinder 4 so when I was plugging the wires into the coilpack the labels for 3 and 4 were backwards. Problem solved!

Now, to call NGK to see why they are marked this way...

 

[DSMunknown]

Huh. Couldn't even get it to start when I purposely switched 1&2 (and then 3&4) when completing my E3 IM install. Would cough and weez, but no start. Had to switch both pairs, and now my order is 3-2-1-4. Stupid coil pack is hooked up wrong. Completely in reverse.

Took me almost the entire day to diagnose.

 

[Freerevving]

glad you got it fixed

 

[snowborder714]

I had called NGK and spoke to someone about the issue. They had no idea why the plug wires were labeled like that. I can't imagine that it would be something specific for a 1g that they would need them labeled backwards, but he said he make note and talk with someone to see if it is a flaw in production or not. He had initially said I may have just gotten a mistake set, but my old set I broke were labeled like that as well.

But, now she's running fine!