rage2

So today, I crossed the 6000mile mark on my 2.8L 106mm big bore block. Everything's been running great, a 2000 mile high speed trek was pretty much flawless (except for a bad batch of fuel, I'll get to that in a bit), and the car hasn't given me any trouble since the day it was completed. There's no smoke out the exhaust, there's no weird bogs or anything, everything is just working really well.

For the first time in years, the car doesn't leak anything! At first, there were some minor oil leaks, the oil sender was loose, and my dipstick o-ring was torn, so a light oil mist was getting all over the engine bay. Not to mention all my clothes stinking like hot oil everytime I drive the car. That's all fixed now.

Oil consumption has been surprisingly high. The car uses about 1q every 1000 miles. I've been opening up and inspecting charge pipes, rerouting catchcans, trying to figure out where the oil's coming from. It looks like a light mist is coming from the compressor outlet. I'm not using a restrictor on my T04E, which may be the reason for the oil from there. Next time the intake manifold comes off, a restrictor goes in, hopefully it'll solve the oil usage problem.

Water consumption has been zero. Always a good thing .

The catchcan has been catching a really really light oil mist, pretty normal stuff. The outlet of the catchcan is completely dry, as is the compressor inlet where it's vented to, so it's doing it's job. About 10 drops of oil for 1000 miles, nice and clean.

The bad tank of gas... on a trip to Vancouver for the FrontEngineFest, I drove through the mountain towns, and they had Chevron 94 octane fuel (for you Canadians that travel the route, it was the Golden, Revelstoke and Kamloops Chevrons in BC). As soon as I put the stuff in, knock was evident on the highway, and boost had to be turned down. By the time I got to Vancouver and filled back up with Mohawk 94, the knock threshold on the mixed good/bad fuel was around 12psi, which made my Vancouver trip a little less fun.

On the way back, once again, I had to use the bad fuel, and once again, the knock was really bad. When checking oil, there was light white froth in the oil filler cap. Didn't smell like coolant, but definately NOT a good sign! Cooling system looked good, no overheating or anything, so just drove it home and hoped it wasn't anything bad. I'll get back to that in a sec...

By Golden, the last Chevron before Calgary, I topped it up and drove home. When I got back, at 15psi it knocked insanely (about 10/sec at WOT). At 12psi, it knocked, about 1 every 2 seconds at WOT. I had to run with the boost controller off, or 6psi to burn through that tank of gas. Once it was nearly gone, I filled up with the Mohawk 94 octane again, and the knock situation improved greatly. At 12psi, there was no more knock, and at 15psi, once every 2 seconds or so. After this tank burnt through, I'm back to my normal 15psi setting. The white froth on the oil cap was also completely gone, even on insanely hard drives .

Back to the milkshake. One of the oddest things that's happened with the bad tanks of gas is what was in my catchcan. There was about 300mL of what looked like coolant + oil milkshake, except a LOT more watery, not nearly as thick. The smell did not smell like coolant + oil either, just smelled like oil and fuel. I checked my coolant level, and to my surprise it hasn't changed at all, at the Maximum mark. I even got some coolant coming out of the overflow when I parked on a very steep hill at my friend's house. So it's not coolant, but it's water from somewhere. Here's my 2 theories as to where it came from.

1. Watered down gas? Does this exist? Everywhere I've looked, watered down fuels apparantly can not happen because the 2 don't mix well, you'll be injecting water and the car just wont start. If there was a lot of water content in the fuel, could it have made it past the rings under boost as moisture, and caught in the catchcan from the positive crankcase pressure relief?

2. High humidity. The weather during the "bad gas" trip was rain. Lots of it. Could that moisture get into the crankcase and separated out by the catchcan? If so, could a week worth of very humid weather account for 300mL of water in the catchcan?

If anyone has any thoughts, lemme know. I'm dying to find out where all that water came from! Once I got back into town and got a few tanks of good gas in the car, there's no more water in the catchcan. Definately scary to see that much crap in there so early on hehe.

Finally, today, to see the condition of the motor, I did a compression test with one of those DIY gauges. 135-137-135-137, pretty much even across the board. Going to do a leakdown test later to see how well these Total Seal rings are doing. Apparantly, guys are seeing 0% leakdown with these rings.

Red1

Well, humidity is always high here. I don't think atmospheric humidity was your problem. 300mL of water would have me very concerned too.

Whether it was water or whatever that was in that gas, I'd replace the fuel filter. Cut it open just to see if anything looks out of the ordinary.

David Floyd

If you have 0% leakage I will be soooo jealous

At 1000 miles, I have 6% leakage and 150 compression across all 4 cylinders.

I don't think humidity is your problem either, I have seen milkshakes in cold weather before.

Just keep a close eye on it

rage2

I'll replace the fuel filter and see how it looks.

As for the sludge, I dumped most of it, but left about 50ml to "separate" itself in a container for the last few days. I just took some pics of it, as well as a small movie to show how watery the stuff was.



Note that the sludge has now separated into 3 distinct colored liquids. The clear watery liquid, the cream colored sludge, and the brown colored sludge. A few days ago, the 300mL of mystery sludge had the same viscosity as the watery stuff, but it was all the cream color. I'm guessing the brown colored stuff is oil.

Here's a quick movie to show how watery it is. Basically, the whole mixture was as watery as the water a few days ago. The cream and brown colored stuff is a lot thicker now with all the water out of it.

http://www.virgeweb.com/rage2/misc/mysterysludge.avi

Kinda scary to find this stuff in the catchcan... glad it's not making any more!

rage2

Is there a reason why my compression numbers are lower than yours, or was it just the way the test was performed? It was my first time doing the compression test myself hehe.

David Floyd

From seeing pictures of your piston tops, ours are not the same design, that may be the reason ??

MPD47

Rage, love hearing about your build. Keep the info comin in.

Crazy Eddie

rage2
Oil consumption has been surprisingly high. The car uses about 1q every 1000 miles.

I have approx the same oil usage( per1500 miles) in my stock turbo S since the day I bought it.
BTW I have a lead foot .... I believe its blow by..... NFI
Regards
Ed

AlexE

That is just weird..........

Although some concerns.

- 300 ml(s) ........... that is a lot of whatever.
- when the knock started to occur........ you turned down boost. Did you adjust your fuel maps?

Product of combustion even bad combustion is water.

So if we were to really think negatively... I would be concerned that some how we developed an overly rich condition. Fuel was washing the walls........ You were having massive blow by (water/combustion etc) Hence the 300 ml(s) of sludge.

Either way......... I don't like that video clip. Made my stomach turn.

rage2

Yea, I have lead foot problems too . Pretty sure it's not blowby, it'd be caught in the catchcan. I tracked it down to a really light mist of clean oil from the compressor exit, so it's being burned off during combustion, therefore never getting to the catchcan.
My fuelmaps are tuned at every boost level. When I turned down the boost, the A/F ratio doesn't change (unless I turn down boost a lot, where I have it tuned to 12.8's in the 5psi range). I had my laptop with me at the time and verified the correct A/F ratios when I turned the boost down.
If the water is from either the fuel, or the combustion, then yes, it'd be a hell of a lot of blowby to cause that sludge. I hope that wasn't the case... that's why I did the compression test tonight to see if anything went wrong. Leakdown tests should tell me more tomorrow.

Kinda bizarre that it just went away as soon as I got a good tank of gas.
You and me both!

I separated the water to another small container, took a sniff, and it smells like fuel, or a fuel additive. Maybe I should try lighting a bit of it on fire... see if it burns. That'll be an easy way to tell if it's water or not!

Duke

Uh, that's odd.
Btw how loud is the knocking when you detect it? Is it clearly hearable from the inside with the windows up?

I always get pain in my stomach every single time I remove the oil filler cap...

hosrom_951

Let me get this straigh rage, that yucky stuff was INSIDE your fuel filter?

rage2

No, that stuff is in the catchcan. Which means it was in the crankcase. The question is where did it come from?

As for the knock, It's caught automatically with the knock sensor and timing retard (I check the displays regularly) well before you hear it. With this bad batch of fuel, it's loud enough to hear with the windows up, which means it's pretty severe.

J Chen

Rage,
Did you perform the compression test
with the throttle at WOT ?
130 sounds pretty low & was it when
the engine was cold ?

Steve Lavigne

Calgary is at 3000+ ft above sea level... I think that explains a large part of the discrepancy.