The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 06-13-2015, 04:21 PM   #26
White70C20
Registered User
 
White70C20's Avatar
 
Join Date: Oct 2012
Location: Kansas and Iowa
Posts: 349
Re: Changing out rod bearings

Quote:
Originally Posted by Jurassic-1 View Post
Is the engine running now? Are you sure it is not a lifter? It could be possible to have oil pressure if it is not too bad . I still would do a bit more research on it and check the oil and filter. You may get lucky and have a collapsed lifter or worn fuel pump and push rod.
I haven't had time to get it running yet. It has 2 year old fuel in the tank that I have to drain. I need to drain the oil and check the filter for metal shavings. It was suggested that I put thicker oil in it and try starting it. I was thinking about using diesel engine oil (15W40) or something like that. I hadn't thought about the fuel pump/pushrod going out. Could that make a hammering/knocking sound? I'll have Monday off, so hopefully I'll get it running then.
__________________
White70C20

1970 Blue C20 - 250, 4 speed
1985 Ford Thunderbird
2005 Pontiac G6
White70C20 is offline   Reply With Quote
Old 06-13-2015, 04:21 PM   #27
White70C20
Registered User
 
White70C20's Avatar
 
Join Date: Oct 2012
Location: Kansas and Iowa
Posts: 349
Re: Changing out rod bearings

Also, it's a 4 speed manual.
__________________
White70C20

1970 Blue C20 - 250, 4 speed
1985 Ford Thunderbird
2005 Pontiac G6
White70C20 is offline   Reply With Quote
Old 06-13-2015, 05:40 PM   #28
Boog
laying low
 
Boog's Avatar
 
Join Date: Mar 2001
Location: Searcy, Ark. USA
Posts: 13,023
Re: Changing out rod bearings

My thoughts on this is use a standard weight oil to get it running. And see what condition it's in.. A heavier weight oil might mask a bearing issue. There can be any number of problems in that engine. It's better to find out right away.
People just don't park good running vehicles. If the owner parked that truck he had to think it had a serious engine problem.
Trying to replace just the rod bearings to keep it going is a crap shoot at best. You would be money and time ahead looking for a good used running engine to drop in it.
305's are out there and cheap. Few people want them.
I don't mean to rain on your parade and kill your enthusiasm but save you some work and money. Setbacks after some hard work can kill a project quick.
__________________
Boog
69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver
primer is finer
91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said.

I stand for the flag and kneel at the cross
Boog is offline   Reply With Quote
Old 06-13-2015, 09:54 PM   #29
White70C20
Registered User
 
White70C20's Avatar
 
Join Date: Oct 2012
Location: Kansas and Iowa
Posts: 349
Re: Changing out rod bearings

Perhaps I should've said this already. After almost everyone who's posted to my thread has advised me not to replace the rod bearings, I've decided not to.

I don't have to work on Monday, I am going to change the oil and filter. Prime the fuel system, and try to get it to start. As Jurassic - 1 said, it very well could be a bad lifter or the fuel pump pushrod making the noise. I personally haven't heard the knocking noise yet. My plan is to get it running, let it idle, and listen to see if I can tell where it is coming from. I don't have access to a mechanic's stethoscope, nor do I have the money to buy one (I have enough for a battery, oil/filter, and a little bit of gas).

One question: if it starts knocking immediately after I start it (which it likely will), how long should I let it run to determine where it's coming from? This is the first knocking engine I've ever dealt with.
__________________
White70C20

1970 Blue C20 - 250, 4 speed
1985 Ford Thunderbird
2005 Pontiac G6
White70C20 is offline   Reply With Quote
Old 06-13-2015, 10:46 PM   #30
tcrist
Registered User
 
Join Date: May 2014
Location: Manteca, Ca.
Posts: 274
Re: Changing out rod bearings

You do not have to have a mechanic's stethoscope. It just makes it easier because you have something your ears to block out other noises. You can use a long piece of wood, a long metal bar or something like that and hold it to your ear while moving the other end around trying to pinpoint the location. Just be sure that you are careful around any moving parts.

Is there anyone close to the OP that can help?
__________________
Terry
Soon to be retired and moving to Bristol, TN.
tcrist is offline   Reply With Quote
Old 06-13-2015, 11:10 PM   #31
White70C20
Registered User
 
White70C20's Avatar
 
Join Date: Oct 2012
Location: Kansas and Iowa
Posts: 349
Re: Changing out rod bearings

Thanks, I'll have to find a long piece of wood/metal.

If it's a lifter, will it be coming more from the top end of the engine? I just want to have some sort of an idea so I can differentiate between a lifter or a rod bearing. Any suggestions?
__________________
White70C20

1970 Blue C20 - 250, 4 speed
1985 Ford Thunderbird
2005 Pontiac G6
White70C20 is offline   Reply With Quote
Old 06-14-2015, 01:20 AM   #32
White70C20
Registered User
 
White70C20's Avatar
 
Join Date: Oct 2012
Location: Kansas and Iowa
Posts: 349
Re: Changing out rod bearings

Quote:
Originally Posted by tcrist View Post
You do not have to have a mechanic's stethoscope. It just makes it easier because you have something your ears to block out other noises. You can use a long piece of wood, a long metal bar or something like that and hold it to your ear while moving the other end around trying to pinpoint the location. Just be sure that you are careful around any moving parts.

Is there anyone close to the OP that can help?
I'm back home for the summer (all my car-guy friends from college are in their respective home states as well).

If it's a lifter, will it be coming more from the top end of the engine? I just want to have some sort of an idea so I can differentiate between a lifter or a rod bearing. Any suggestions?

If it's the fuel pump I'll replace it. If it's a lifter, I'll just drive it (maybe it'll pump back up). If it truly is a spun rod bearing, I won't run it very long. I'd like to be able to differentiate a rod bearing knock from a lifter knock.
__________________
White70C20

1970 Blue C20 - 250, 4 speed
1985 Ford Thunderbird
2005 Pontiac G6
White70C20 is offline   Reply With Quote
Old 06-14-2015, 07:33 AM   #33
jjzepplin
Registered User
 
jjzepplin's Avatar
 
Join Date: Feb 2012
Location: Ruskin Florida
Posts: 4,549
Re: Changing out rod bearings

Ticking=top end. Thumping=bottom end. Ticking=fixable. Bottom=rebuild.
__________________
70 swb 4x4 406sbc 700r4 203/205 d60/14blt locker yadda yadda http://67-72chevytrucks.com/vboard/s...88#post6935688 Yeller
72 Blazer 2wd conversion project "No Daggum Money" http://67-72chevytrucks.com/vboard/s...d.php?t=550804 LS1-T56 3.73 LSD super budget build
Blanco-2014 Sierra SWB https://67-72chevytrucks.com/vboard/...d.php?t=810350
jjzepplin is offline   Reply With Quote
Old 06-14-2015, 10:32 AM   #34
tcrist
Registered User
 
Join Date: May 2014
Location: Manteca, Ca.
Posts: 274
Re: Changing out rod bearings

If it is a lifter what you will probably be hearing is a loose rocker. That would be under the valve cover on each side of the engine. It might also be heard from the intake area next to the heads.


Remember, what your friend calls a KNOCK might not be a knock to others. There are different depths of knocks. Hard knocks & soft knocks to even just a rattle.

Where is home now? Maybe someone from the forum is close and can help. If you were close I would help but if you are in Kansas or Iowa that would not work out.
__________________
Terry
Soon to be retired and moving to Bristol, TN.
tcrist is offline   Reply With Quote
Old 06-14-2015, 12:20 PM   #35
White70C20
Registered User
 
White70C20's Avatar
 
Join Date: Oct 2012
Location: Kansas and Iowa
Posts: 349
Re: Changing out rod bearings

Thanks! I appreciate the offer. I'm home in central Iowa (college is in central Kansas) for the summer. I'm only going to be able to work on the truck in the evenings since I start my summer job this week. It'll be odd hours, so I think it'd be hard scheduling someone from the forum to come here to help.

I've still got all afternoon today and all day tomorrow to get it running. With the new knowledge I've gotten from all of you guys I should be able to determine where the knock is coming from.
__________________
White70C20

1970 Blue C20 - 250, 4 speed
1985 Ford Thunderbird
2005 Pontiac G6
White70C20 is offline   Reply With Quote
Old 06-16-2015, 12:21 AM   #36
White70C20
Registered User
 
White70C20's Avatar
 
Join Date: Oct 2012
Location: Kansas and Iowa
Posts: 349
Re: Changing out rod bearings

It's alive!!! After sitting for two years in my friend's backyard, I was able to get it started. And Good news!!! It's more than likely not a spun rod bearing that was knocking. When changing the oil yesterday, I noticed three penny to nickel sized holes in the Y pipe. Boy did it make a racket when I started it up. I can see how my friend thought it was a bearing knock.
Now as soon as I can get all the lights to work I can go out for a drive!
__________________
White70C20

1970 Blue C20 - 250, 4 speed
1985 Ford Thunderbird
2005 Pontiac G6
White70C20 is offline   Reply With Quote
Old 06-16-2015, 12:25 AM   #37
GRX
Registered User
 
GRX's Avatar
 
Join Date: Jul 2010
Location: MD
Posts: 1,937
Re: Changing out rod bearings

Exhaust leaks? And you got us all worked up over rod bearings for nothing. But seriously. Good news!
GRX is offline   Reply With Quote
Old 06-16-2015, 12:27 AM   #38
White70C20
Registered User
 
White70C20's Avatar
 
Join Date: Oct 2012
Location: Kansas and Iowa
Posts: 349
Re: Changing out rod bearings

Quote:
Originally Posted by GRX View Post
Exhaust leaks? And you got us all worked up over rod bearings for nothing. But seriously. Good news!
It would appear so. I really did appreciate the advice and suggestions.
Thanks again!
__________________
White70C20

1970 Blue C20 - 250, 4 speed
1985 Ford Thunderbird
2005 Pontiac G6
White70C20 is offline   Reply With Quote
Old 06-16-2015, 07:18 AM   #39
hamjet
Registered User
 
hamjet's Avatar
 
Join Date: Apr 2013
Location: South Westerlo, New York
Posts: 1,325
Re: Changing out rod bearings

I still say its a rod bearing. tear the engine out, and as long as you're at it go for another tranny, gotta play it safe ya know... Just kidding, happy day, good luck and happy motoring...
__________________
Thanks, Joe..
1969 C/10, 348 C.I., 3X2 bbl. V8, 2004r , LWB.
hamjet is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 12:42 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com