54 replies to this topic

[dB_Outlaw]

So I went to drive the trix this morning for its weekly run. Starts a little belabored, no biggie but her idle tone is lower (bassy-er) than normal. Idle is at 1k, that's normal. Figured I'll let her warm up (always do) and re-evaluate her tone. 2 minutes later she sounds the same. Gave her some gas and even the rev sounded different. Drop her in gear and put around in first. Coasting or with a little throttle, her note is off. Parked her and checked the battery voltage, good. Going to check the oil when I get home but she was just serviced in April.

My AFRs were good at idle, 13.x. Engine temp looked oK but then again she only ran at most 10min. Ideas on what to check? I'm guessing something went wrong with the ECU or tune.

[kpace]

you're breaking my heart man

[dB_Outlaw]

Tell me about it. I was like WTF, that doesn't sound right; and I drove her normal last Friday because I wasn't in a speed racer mood.Year and a half w/o problems and now this!

[Roxtar]

exhaust leak?

[dB_Outlaw]

I had an exhaust leak prior and you could hear that damn thing hissing like a mofo. The trix actually sounds quieter than normal.

I can get a before/after exhaust note this weekend if you all think that will help.

[edit] Just googled exhaust leak symptons; some of those fit, some don't *and* my community is under construction and only 1 layer of asphalt. Exposed manholes all over the place. I tagged one a few weeks ago but didn't notice anything until now.

Edited by dB_Outlaw, 13 July 2012 - 07:41 AM.

[adamderry]

Intake filter?

[dB_Outlaw]

There is no intake on my turbo do to the way it's orientated (there's no room). Just "chicken mesh" wire covering the turbo intake.

I refuse to think it's anything catastrophic but I don't have money to get it looked at. Maybe next month. Until then, it'll sit in my garage with the hood up; the universal sign of distress.

[dB_Outlaw]

Ran the engine after 3 weeks of sitting and the exhaust note hasn't changed. Usually she sounds like a vacuum cleaner now she sounds more like a washing machine. I took a video clip of the tone.





Exhaust leak?

[edit] after watching that I see I'm not making any boost when I rev it in neutral...

Edited by dB_Outlaw, 29 July 2012 - 11:33 AM.

[HaZzArD]

At the lower RPM's it sounds like a boxer engine lol.. have you looked under the car to see if there are any noticeable leaks.

also you shouldn't have boost when you rev the engine, it should go close to 0.

[dB_Outlaw]

I glanced down there w/o jacking the car up and didn't see anything. Need to get a friend over with a industrial jack to get her up on stands and take a look.

[HaZzArD]

If your exhaust has sections to it (like the stock has the mid-pipe section, then the axle back section) I'd probably check at where they bolt up to each other if you don't see any holes. Just put your hand by it while the cars running to feel any puffs of air coming out. Then i would check the turbo manifold and down-pipe bolts so see if any have come loose.

Have you driven it since then? Does it drive like it the previous times?

[dB_Outlaw]

I drove it but never got out of first gear because it didn't sound right. I wasn't really concentrating on the power aspect. However, I did notice after starting it this last time and giving it some throttle, she hesitated badly and the rpms wouldn't budge until I gave her more throttle, maybe half. Did that twice but after it was warmed up (and I shot that video), she rev'ed fine. This also points to a small leak someplace that after the pipes heat up and expand, closes the hole/gap.

[Evilthorne]

Compression test.

[dB_Outlaw]

Finally got it looked at today. No exhaust leak. Looks like a bad spark plug because only 3 cylinders were firing. Going to replace the set with another batch of NGK BKR7E unless someone has a better recommendation.

[dnm]

The best way to answer that is to look at the plugs that are in there right now.

bkr7e is 2 ranges colder than an oem 1zz calls for -- this may be perfect for a built turbo application like you have going on, but a good identifier would be any indication of carbon fouling or overheating on the plug.

[Roxtar]

here's a pic that show what you're looking for:


carbon deposits indicate your heat range is too cold, that white crap indicates that your heat range is too hot.

[Evilthorne]

Lets see the bad plug though, I would be worried about the pre-ignition picture where the electrode is melted or blown off.

[dB_Outlaw]

I glanced at the plug and the electrode looked OK. Even my backyard mechanic said it looked OK. We switched the plug to another cylinder to check and that one started misfiring. We also moved the plug harness and spark plug from c2 to c1 and c1 was firing OK. Moving the "bad plug" back to c1 and the misfiring occurred again (in c1) but it started to be intermittent. Mechanic's recommendation was to replace the plugs and go from there; otherwise it could be an engine problem.

Side comment. Both cylinders 1 and 2 had a loose screw beneath the spark plug. WTH is this? I assume the other 2 plugs have it as well.

[dnm]

A loose screw?

[Evilthorne]