Harsh timing rattle first few seconds of running?

[AcIdBuRn02ZTS]

Ether yes... just a light tap on the nozzle... Baiscally just enough to put a sniff in the intake is all it takes to kick it over. Only reason I didn't consider this as a cause as the sound lasts for 30 seconds or so and it doesn't have that ether "knock" to it. The sound is basically inbetween normal diesel rattle and ether knock. Lol..

I'm gonna say its nothing to worry about at this point. I'll let it be and just keep an eye on things until I can get a few miles on it and get everything buttoned up.

Thanks for the input guys
-Chris

 

[79jasper]

Was this engine recently rebuilt?

Maybe do a compression test, otherwise doesn't sound like anything to worry about.

Sent from my SAMSUNG-SM-G935A using Tapatalk

 

[AcIdBuRn02ZTS]

160k on bottom end... fresh heads, gaskets, etc... Engine did the same with the original heads on it. Engine has only been in the truck a few weeks.

Seems to run great... no smoke/haze, no odd noises other then the timing rattle... no oil usage or blow by.

 

[AcIdBuRn02ZTS]

Pump was removed when heads were replaced. The engine made the same noise prior to pulling heads however. This engine has only been in the truck a few weeks. Valve guides were bad so hears were replaced.

Before pulling the heads, I put the timing meter on it as it had the harsh rattle all the time. Put the meter on it and it was running 15° adv. I pulled the timing back but it still had the rattle at start up, but would calm down after 30 seconds or so like it's doing now.

Mainly, I wanted to know if air intrusion could advance the timing and cause the rattle. It would make sense as it clears up after running just a bit.

Now, I haven't had the GP system functional since day 1, so that could also be the issue.

It sounds exactly like when we bumped the timing up on a buddy's truck and the cold advance was on... Just a marble like rattle... Not a metallic sound or anyting of that nature... And no running issues thus far.

 

[Clb]

I think it was mel or gary' the govner sees lack of fuel and pinns the advance to get going again(iirc)
Good luck, have a good one , sounds like its under control!

 

[icanfixall]

Yes.. Air changes the amount of advance. So does high fuel pressure into the injection pump. If it was 15 degrees advance what is it now.

 

[Clb]

Btw
Last I heard...
15Deg is glowplug melt territory( might wanna pullem)

 

[AcIdBuRn02ZTS]

Glow plugs are new motorcrafts and run time was minimal. I had them out when I pulled the heads and they looked fine.

So, I put the meter on it tonight which I hadn't done since pulling the heads... Low and behold, it was almost 16° advanced.

I pulled the timing back to 8.5° and set idle to 750. Warm idle sounds great and smooth with a very light rattle. Won't know if it fixed the cold start rattle, but I'm betting it helped.

After jumping timing down, I let the truck run as I tinkered with little things and checked everything over. It ran for another 45 minutes and no major issues that I can see.

I'll know more as far as the rattle goes come tomorrow.

 

[Clb]

The good old ... Time it first issue.
Hope this fixed it.

 

[AcIdBuRn02ZTS]

Yeah... I shouldn't have jumped to conclusions and it didn't sound like it was that high when warm.

Oh well.. Live and learn.