Road trip, and my Motor ran very differently

[Isaiah92260]

So my 67' 250 straight 6 Tends to Idle pretty noisy because either the Valve guides are bad or my cam is worn and the lifters arnt getting full motion.
Anyways today I took a 50 mile trip down the highway going 60 the whole way. Right when I finally rolled in and parked the truck, I lifted the hood, and I swear the 250 was idling so quiet and smooth.... how is that possible?! Ha

[TJ's Chevy]

Sometimes a good drive helps burn all the carbon out. Doesn't have Valve Guides so you know. Anyhow, it'd be the lifters making the noise. A flat cam won't cause valve train rattle, but a loss of power and poorer performance. A good drive never hurts.

EDIT. Does have Valve Guides....my mind read Pushrod guides. Wonder where I was. lol

[Isaiah92260]

Originally Posted by TJ's Chevy

Sometimes a good drive helps burn all the carbon out. Doesn't have Valve Guides so you know. If someone told you it does they need to look at a picture. lol Anyhow, it'd be the lifters making the noise. A flat cam won't cause valve train rattle, but a loss of power and poorer performance. A good drive never hurts.

Oh wow I had no idea it doesn't have Valve guides, I'm still learning a lot about these motors. Thank you for mentioning that! A family friend who is a motor head told me the other day I should put a quart of diesel in my truck, run it for a good 20 minuets half hour to get the engine hot, then when I park it, drain the oil right away, which would clean out the engine damn good he said. What are your thoughts on that? I might just do that soon

[Mackie]

There are risks with thinning the oil to flush out sludge. Firstly, I wouldn't drive it 20-30 min. but let it idle. Alternatives to diesel are ATF and Rislone. Rislone being the safest. Also, a risk is dislodging sludge can clog the oil pump pick up screen.
I personally have done this on a "not much to loose" engine and it helped unstick hydraulic lifters.
Multiple mild treatments would be safer, no more than 1 qt.
The long run you gave it probably cleaned out carbon build up as said. Google Sea Foam dribble in carb method for even better carbon cleaning.

[Isaiah92260]

Originally Posted by Mackie

There are risks with thinning the oil to flush out sludge. Firstly, I wouldn't drive it 20-30 min. but let it idle. Alternatives to diesel are ATF and Rislone. Rislone being the safest. Also, a risk is dislodging sludge can clog the oil pump pick up screen.
I personally have done this on a "not much to loose" engine and it helped unstick hydraulic lifters.
Multiple mild treatments would be safer, no more than 1 qt.
The long run you gave it probably cleaned out carbon build up as said. Google Sea Foam dribble in carb method for even better carbon cleaning.

Thank busy for that! I've heard about sea foam.... how does that work?

[66Submarine]

Well, it does have valve guides, just not replaceable ones. If the valves were just floating around it would get interesting pretty quick, lol.

As noted, the ticking at idle is probably the hydraulic lifters clattering a little from collapsing slightly and adding lash to the valvetrain. For whatever reason they pumped up when you drove it today.

Not an uncommon issue at all. Also commonly transient, as you've observed.

[TJ's Chevy]

Don't know where the hell I was that day.....thought he was taking about Pushrod guides for whatever reason. Derr.....I'm a go back in my corner now.

[66Submarine]

Originally Posted by TJ's Chevy

Don't know where the hell I was that day.....thought he was taking about Pushrod guides for whatever reason. Derr.....I'm a go back in my corner now.

You can come out when your truck is fully reassembled

[Isaiah92260]

Originally Posted by TJ's Chevy

Don't know where the hell I was that day.....thought he was taking about Pushrod guides for whatever reason. Derr.....I'm a go back in my corner now.

No worries brotha lol

[Isaiah92260]

Originally Posted by 66Submarine

Well, it does have valve guides, just not replaceable ones. If the valves were just floating around it would get interesting pretty quick, lol.

As noted, the ticking at idle is probably the hydraulic lifters clattering a little from collapsing slightly and adding lash to the valvetrain. For whatever reason they pumped up when you drove it today.

Not an uncommon issue at all. Also commonly transient, as you've observed.

Thanks for your insight, yeah those damn lifters sounds like crap on some days, do I have to pull the whole head off the motor to replace the lifters?

[jtrichard]

TJ we all have them Homer Simpson moments DOH!