Newly rebuilt 308 QV engine- Does this sound right?

This engine was recently rebuilt and was started up for the first time about 3 weeks ago. It now has about 8 miles on it. Everything is stock except for the high-compression(10.5:1) JE pistons and the exhaust headers.

Here is a video I shot this morning:
[ame]http://www.youtube.com/watch?v=XnKr6CF6w7Y[/ame]

I'm concerned about the clickity-clack noise from the top of the engine. Do you guys think this sounds normal? If not, what do you think is the problem?

Thanks!

 

Sounds bad to me. Also sounds like its in the top end.

Make sure it does not have a exhaust leak before you pull the engine back out again, as thats the only easy fix that i can think of. ( if its not inside the top of the engine)


I would NOT run it anymore.

Have you rotated it by hand to narrow down the noise?

 

Doesn't sound right at all. I wouldn't run it again but take it to the shop that rebuilt the motor and have them figure it out. If that's not an option check for exhaust leaks, that the check vavle below the oil filter has the right air flow direction (arrow pointing to the drivers side), check the wires for crosstalk and correct firng order and also check the exhaust for obstruction like a mouse nest. Check to make sure you have oil pressure too.

 

when i started my motor after my winter service it sounded 10 times worse then yours....it was an exhaust blockage.

 

How in the heck did it leave the shop sounding like that? If they are not out of business now, they should be.

Although it's hard to tell from the sound on the computer, it has a clackety valve-related sound to me and might be really loose valve clearances though it could be multiple header leaks at the ports. Header leaks usually have more of a "snap" sound than the clack sound but again, audio on a camera video and played through computer speakers is not very accurate soundwise so it's hard to tell.

You said they put in high compression pistons - did they clearance check the valves to the pistons or just install pistons that were "supposed to work" and left it at that? I know from experience that it is possible to have an engine running where the valves are just kissing the piston tops and you will get that sort of clatter but once the engine gets hot and gets some serious throttle, it will come apart.

 

I know it can take a second to get the light to go off and the gauge to come up, but in the second that the video shows the gauge and light, the light stays on and the gauge doesn't move. That changes when the engine is running, right?

It also seems odd when cranking. It cranks pretty quickly and then bogs down and then starts. Seems like a clue. Clogged oil cooler? When the cooler pressureizes the oil pump drag slows the starter? Purely a guess.

 

Wow, I went back and took note of that as well. That does sound very troubling, doesn't it? Did the engine sound like that from the beginning? I'll be watching this thread to see what happens...

 

Yikes!!! It does sound like it is coming from the valvetrain. But, it does seem odd that the cranking does suddenly slow down...could be exhaust blockage like OP had mentioned...it takes a second or two for the pressure to build up in the exhaust.

Good luck.

 

Valve train clearances or incorrect piston to wall clearance sounds like the issue. Also, with 10.5:1 compression you want to back off on total ignition timing which unfortunately is sort of tricky with a QV. The problem is with that compression the combustion efficiency is such that it can no longer handle (without the possibility of detonation) the stock ignition timing. Be careful but if it were me I would back out a couple degrees at max advance.

 

I hope that engine has oil in it!! Have you measured on the dipstick?

 

Yes, the engine has oil and oil pressure. IIRC, the pressure was 1 tick below the 85 on the gauge. These are all good suggestions. My friend who built the motor is currently out of town, but when he gets back we'll do some troubleshooting.

Thanks for all the replies and keep them coming if you think of more stuff.

 

Ask you friend if his tools are all accounted for

 

If you've confirmed you have oil pressure, go for the obvious and simple to check. Make sure all of the nuts & bolts in the exhaust system are tight. An exhaust leak or two will make any engine sound horrible-and can often be confused for more serious problems.

 

On a lighter note, I really like the tan dash.

 

Report back with your updated fuel mileage in your new diesel 308.

 

Any news?

 

I think I can speak for the poster here as I have some news on this.

I spoke with the poster a week or so ago and we went over clearances. The clearances were checked within the past couple days and it was found that a few were not where they were supposed to be with one being very out of whack (.025 clearance!).

 

Yep, my mechanic and I checked the valve clearances last night. For the most part the valves are slightly loose. The spec says intake should be .20mm-.25mm and exhaust should be .30mm-.35mm.

My intake valves mostly range from .25 - .30 mm exept one was .20mm- .25mm, one was right at .30mm, and one was about .32mm.

My exhaust valves mostly range from .35mm-.40mm. Three were a bit tight: one was .28-.29mm, one was .30, and the other was .31mm. One was very loose: it measured .66mm.

So probably that loose one was making most of the noise. I'm going to bring the clearances back into spec and let you know if that helps the engine sound.

 

good luck . i would at least pull off the oil filter and cut it open for inspection / metal, as well as consider changing the oil again.

 

If the valves were set when the engine was assembled I would do a leak down NOW! Lost

 

If the valves clearances are that far off, I'd wonder what other tolerances might have been missed when the engine was put together. Just sayin'.

 

Worst sounding engine I have ever heard. I'd be removing it and starting again ... or atleast removing all cam covers and sump and checking things.

Pete

 

idn guys if sounded funny when it was being cranked over ....... it did not sound right when the starter was being engauged ........just from what i can hear maybe a starter and flywheel issue........but in order to be sure i would use a stethoscope to see where the noise is coming from.........just my thoughts

 

that doesnt sound ., at all ., right,,,hope you sort it out,,,

 

FerrariPilot and I talked about this a few days ago, but I was just able to get on here to see this thread!!

Yikes!! Thats a bit scary!!!


Please do keep us up to date and let us know what happens with it all!!!





PDG