Blew up my LT5, Let the grieving begin.

[Paul Workman]

I spoke to Marc briefly about your experience, and he told me that in his experience there is a tendancy for people to jump to conclusions - thinking they broke the motor - where he finds that to rarely be the case: something else is causing the problem (problem being spinning a rod or main bearing, that is). Hell, one of my first experiences with the Z was some spark cross-over due to mice having chewed my (LT5) wires. Talk about knock!

Could have injested something, or dropped a valve, or broken dual FW spring... No need to think the worst, is what we're sayin', I recon!!

Whats new? What have ya found??

P.

[scottfab]

Originally Posted by Paul Workman

.....snip....
Whats new? What have ya found??

P.

Yah, we're curious about the outcome.
Hope its just a spark plug fouling or something simple.

[Torchred96]

Ok, I'm back. Thanks for the patience. I read and re-read all of your responses, also looked at some video of OH cam collapsed lifter video on youtube and went back to my engine with a renewed sense of optimism.

Observations: When I start the car (yes i did), there is a definite KNOCK that goes away after OP builds up (oil pressure comes up quickly and is right in the middle of the gauge). The knock then goes away and a ticking noise remains. I can't start the car and listen with a screw driver at the same time so it's hard to tell where the knock is. I would guess that knock and tick is at half the freq of the rpms, because when it goes down to a slow idle, i can follow the cadence of ticks and can rapidly say the word tick tick tick tick as it happens (if that makes sense) ...Another way I could describe the tick it is that I can count up to about 1,2,3 and then my mouth can't quite move that fast...So,at least to me it doesn't sound like it's happening once per revolution, but rather, every other revolution

Oil level is at the ADD mark...I thought i was pretty good at keeping oil in it but the oil pan was damaged at one point and it loses oil through what appears to be a bad jb weld repair. I never noticed any loss of pressure though.

1st. Reassured myself that the front accessories were not spinning and eliminated those as a culprit. i.e. I loosened the belt, started it (i know I know) Though the wp is noisy, it is not the noise in question.

2nd. I thought I may have injested a screw from the throttle plates as I used another type of screw to put them back on after the powdercoat. The screws were still firmly attached to the throttle plates.

3rd. Loosened all plug wires enough to pull them easily when started. I believe all cylinders on the pass. side dropped a few rpms each when wire removed with no discernable change in ticking noise. However, on the driver's side, though it was more difficult to discern, it seems like cylsl 1 and 3 (definitely 1) don't chage rpms much at all. But then 5 and 7 are not much better. There was NO noise difference with the wires pulled that I didnt attribute to the flywheel noise I used to hear when it was Missing due to the injectors, and the ticking remained.

4th. Looked at the harmonic balancer while running. It seems to track fine, no obvious damage or noise coming from it.

Next, I used the screwdriver handle to the ear. I had used a medical stethescope before but I think this trick works better. I think I found the ticking noise on the driver's side cylinders esp (noise directly under cam cover of) number 1, but can hear it all the way down the length of the cam cover on that side. The noise when directly over the number one cylinder sounds like a "thick thick thick", IE, like a slapping tick so I'm guessing it is in the valve train on that side.

ON the pass side, I can hear the tick, but is sounds more like it's traveling through the aluminum engine..It's much more pronounced on the drivers side.

I was going to remove the oil pan this evening, but after I got it jacked up and put on stands, I decided to try one more time and do the above tests.... I hope this is good, or at least better news.

Again pls forgive me for not getting back to you faster. I wanted to assimilate what you guys said, weigh the alternatives (buying a new engine, sell the car (not really an option since I owe too much on it) etc) and also get motivated to jump in ......again.

I haven't cut open the filter or drained the oil, but there are no obvious fragments in the dipstick oil held up to the light.

That's all I got for now. Maybe as Paul said, I may have over reacted and assumed the worst. Hopefully, it's not a rod, main bearing or piston (it definitely doesn't clunk after op is up even if I bring r's up a little bit.. ticking persists at all rpms though.

Any thoughts? Thanks again!!!!!

[Blue Flame Restorations]

Sounds like you lucked out. Time to open her up.

I suggest to WELD the oil pan and eliminate future issues.

I have a good 1990 style oil pan if you want to exchange it. I'll repair yours and shelve it.

[Torchred96]

Thanks Brett. I'm glad to hear you say that. I wasn't sure if it was as good as I thought it was. As far as the oil pan, after I confirm that I can fix the damage to the valve train (if that's what it turns out to be), I'll just have the pan welded locally, but that is a very generous offer. One reason that I will probably never sell the z is because of this kind of support. You won't find that with the other gens.. guaranteed. Thanks again!

[scottfab]

I sure would think a try with thinner oil would be a cheap test.
Dump some engine cleaner in before dumping the thick oil. (15w50)
Then runt he engine like they suggest on the can for X minutes before draining. The ticking sure sounds like lifter.
Can you make an audio recording and post?
It's difficult but doable.

[XfireZ51]

Have u thought if using Marvel Mystery Oil in the crankcase?
Put in a quart or so and run the motor. Used it many times to unstick a lifter.

[Torchred96]

I have no problem trying that, but would that happen to an engine that is running on a weekly basis and was running fine when I took it out that day until I got it home?
Also, I have some diesel in the garage, would that work instead of M.M.O?

[scottfab]

Originally Posted by Torchred96

I have no problem trying that, but would that happen to an engine that is running on a weekly basis and was running fine when I took it out that day until I got it home?
Also, I have some diesel in the garage, would that work instead of M.M.O?

I'd use stuff made for removing sludge like Gunk brand or
http://www.auto-rx.com/

I ran it twice as long as recommended and the lifter noise went
away in mine. FWIW it was on the same side as what you're describing.
I went back to 10w30 with one quart of 10W40.
All was penzoil untra fully synthetic.
I find that the one quart of 10w40 lowers oil consumption on my 90.
As is common knowledge 90s have no exhaust valve seals.
It also quiets the CCT noise on start up.

[Torchred96]

I just decided to go ahead and start to disassemble. I won't be breaking any speed records though.

Gonna start a new thread in tech since I'm sure I will have questions. ..actually already have questions, but I'll save 'm for tech

Thanks for the support...wish me luck