Instant Death

[turbo_brian]

Ok, have an RB26DETT R32 Skyline, was working wonderfully until 2 weeks ago.

Went out with a few friends on the Sunday, off to the RSL for some drinks, some pool, and just to enjoy time with mates.

Went home, car was brilliant the entire time, no issues, good power delivery, a pleasure to drive.

Woke up the next morning, did the usual thing, got to car, unlocked it, fired it up, opened the boot, put my crap in the boot, came back, checked all the warning lights where off, there was no un-natural or abnormal sounds, spent another 20 - 60 seconds putting on seatbelt, changing radio station, and setting everything up to drive to work (the general morning ritual to allow the engine some time to get the oil around and warm up.

This morning, all was good, drop out of the drive nice, and I did the usual crawl until the termpature gauge started to rise.

Once the temp starts to rise, I went to put some more power down, but it didn't feel right, it struggled to pick up.

Checked the boost guage and it was pushing into positive boost, but struggling, felt sluggish, nd the exhaust note wasn't correct.

At this point, I dropped the mrs off at the train station, and took the car to my local mechy.

Did a compression test, 155psi +- 4psi on all 6 cylinders, so compression was sweet, and on went the diagnostics.

Today, he calls me saying the turbo was loose on the back, he has tightened the turbo, and is going for a test drive. After popping in to see him (he's a good friend), turns out the car shut down on him during the test drive and he hasn't had a look at it, so we both push it into the workshop, remove the coil packs, remove the plugs (covered in fuel) and do a compression test, and it's dead 0 on all 6 pistons.

I am at a loss, I can understand something going wrong and loosing a complete piston, but to loose all 6 is just not right.

We removed the cam covers to make sure both cams where turning when the engine was being turned over, and they are, so it's not a broken timing belt that has left the valves open.

Did ECU diagnostics, it revealed no error codes at all.

I am at a loss for idea, anyone else had issues like this or could help me out???

Thanks,

Brian.

[2LV8ETR]

I can't understand the compression dropping on all 6!? Maybe it's a fluke and the compression tester crapped out on him. Maybe try it on another vehicle??

As far as fuelled up plugs go, to me that points to ignition. Maybe the ignitor?

Doesn't seem to me that she should go like that so easily.

[Cjmartz2k]

I don't think even a popped head gasket would show 0 on all cylinders. Maybe it the belt slipped a tooth and trashed the valves into the pistons?

[turbo_brian]

I don't think even a popped head gasket would show 0 on all cylinders. Maybe it the belt slipped a tooth and trashed the valves into the pistons?

This is my thoughts, When starting to take the belt cover and CAS off, we found adjustable CAM gears hidden away inside, thoughts are that one of the cam gears might have loosened, causing the inlet or exhaust to go way out of timing, and thus mash the valves, leaving them not closing, thus 0 psi compression, which means no voilent combustion.

He's going to get his optical camera into the cylinders tomorrow and check the piston heads for signs of contact (camera doesn't bend back enough to see the valves themselves), and we can go from there.

Chances here are that head will be coming off, which means I might as well start looking at porting the heads, have a think about upgrading CAMs (especially with adjustble cam gears in there), and potentially high-flow the turbos while everything else is apart, but looking compression in all 6 pistons to me just isn't right, sounds like a timing issue.

Just glad it was polite enough to drive straight to the mechanics before bombing out, and it was nice it bombed on him, and not me.

B.

[a31lunacy]

the sluggish thing i would point at the cas drive maybe being worn and causing this but as for zero compression im at a loss

[Cjmartz2k]

This is my thoughts, When starting to take the belt cover and CAS off, we found adjustable CAM gears hidden away inside, thoughts are that one of the cam gears might have loosened, causing the inlet or exhaust to go way out of timing, and thus mash the valves, leaving them not closing, thus 0 psi compression, which means no voilent combustion.

Were they HKS cam gears? Contrary to popular belief, not everything HKS puts out is even half way decent. I have seen their cam gears kill 2 motors. They only have 3 little bolts holding them in place. Really need to crank them little buggers down.

[The Dan]

Before you take the head off you need to do a leakdown test. That will tell you why the cylinders are not making compression.

You can try something also.

Take the pipe off the plenum, cover it with your hand and get someone to crank over the engine. See if it tries to suck your hand in. Be careful you don't injure yourself. It can't swallow you hand but it can crack a knuckle .

I think, though, you will find the leakdown test will reveal your problem.

[Cartman]

i'm leaning towards snapped/shredded timing belt, all your valves are most likely bent as they are an interferance motor

[Guilt-Toy]

i would have taken the front covers off first & inspected the belt and timing before even worrying about the turbo if it was my car.

[turbo_brian]

Were they HKS cam gears? Contrary to popular belief, not everything HKS puts out is even half way decent. I have seen their cam gears kill 2 motors. They only have 3 little bolts holding them in place. Really need to crank them little buggers down.

Unfortunately they are HKS Cam gears, I did not install them, and didn't actually know the car had adjustable cam gears when I bought it.

I guess it's leak-down test time, and if this reveals mashed valves, it's a rebuild.

Bloody bad timing with a wedding in less than 6 weeks, but what can you do.

Thanks guys, when I find out more, I will post it up.

B.

[The Dan]

It's practically impossible to smash every valve when the belt breaks.

Once it breaks, the cams stop turning. It can smash every valve if the belt stays on but a bearing lets go causing the belt to loosen

[W0rp3D]

i would have taken the front covers off first & inspected the belt and timing before even worrying about the turbo if it was my car.

I also would have gone that route to check the cams instead of pulling everything else off.

I personally think the problem will be something odd.

Edited April 30, 2009 by W0rp3D

[Cjmartz2k]

Well, crappy HKS gears sliding all the way to the extreme of adjustment on there own could throw it off enough o trash the valves while keeping everything still turning and screwing the rest of them up.

I would rather run cheap ebay knock off timing gears than those HKS pieces of crap. Unfortunatly, my cams have already been dialed in with them, so my HKS cam gears are going to stay put for the next couple months.

[James_03]

+1 for smashed valves.

[turbo_brian]

i would have taken the front covers off first & inspected the belt and timing before even worrying about the turbo if it was my car.

Timing belt was checked when the car was first dropped off, thoughts at that stage was belt jumping a tooth, and tension arm failing, so the cover was removed, belt tension checked and found strong, belt in decent condition, so everything was put back together, compression test performed (156, 154, 155, 154, 153, 155), and then on inspection, the rear turbo was seen to be missing 2 bolts, and the rest where almost at the end of the threads, this is where focus changed on the investigations.

At this point, turbocharger was re-mounted, 2 new bolts fitted, and the car was taken for a test drive.

It was started, warmed up a little but allowing it to idle for a few minutes, and then driven around the block. It surged and dropped power, then gained power, then cut out completely (800 meters down the road from leaving the workshop).

It was pushed back. When cranking it over, it sounded higher pitched in cranking than normal, almost like it wasn't struggling to turn over (struggling against compression), so it was pushed back into the workshop, coil packs and spark plugs removed, and compression test re-done to reveal 0 PSI in all 6 cylinders.

B.

[DAN00H]

+2 for bent valves (piston/ valve contact). bore scope will be able to show contact with piston crowns if this is the case.

[R31Nismoid]

It's practically impossible to smash every valve when the belt breaks.

Once it breaks, the cams stop turning. It can smash every valve if the belt stays on but a bearing lets go causing the belt to loosen

Almost impossible although I smashed/bent 18 about 7 years ago when my bearing tension thing let go - could be a record...

[E-Z]

my tensioner snapped on sunday, thought id smashed the engine, i cranked it over to restart the car also. put a new tensioner on and bam all sweet, (vg30det) i thought my engine was interference but must not be, unlucky mate, just a thought but, if the cam gears cam loose surely they dont have enough adjustment to mash valves?

[PM-R33]

Really curious to see what caused this....

[Beer Baron]

bummer. my advice for ANYONE who fits ANY BRAND of cams gears is to check them 4 weeks after installation. being alloy there is always some 'give' in them. you tighten the bolts on installation but they can and do come loose. on one of my 32 GTRs. big build in japan. brand new crate motor, fully built from new, HKS turbos, 600ps all the good gear, cams, springs, head work blah blah blah. about 2 months after it was built we checked the cam gears. sure enough the bolts had loosened off. and these were tomei gears which run 5 bolts (i only use the 5 bolt jap gears, either tomei or trust). well worth checking.