engine sounds/possible rebuild??

tetoncruiser · 07-02-08, 07:51 AM

my 80 only has 65k miles and it is beginning to have a very minor low end sound (only during starting up) and another higher pitched cracking sound when towing and accelerating up hill when the engine is warmed up. oil pressure seems to be read 1/4 to 1/2 under acceleration. hoping it is not a rod....any thoughts???

Beowulf · 07-03-08, 12:02 AM

You should strive to give us more information. Which engine do you have? What year model? Can you be more specific on the sounds? It is virtually impossible to remotely diagnose a potential problem based on someone's verbal description of a sound so you will need to do a MUCH better job than a "low end sound". That doesn't tell us much. Low end of the sound spectrum? Low end as in the lower part of the engine?

Also post a pic of the oil pressure gauge where you think it is a problem. A picture is worth a thousand words and your "1/4" might mean something completely different to me.

Any history on the truck?

-B-

tetoncruiser · 07-03-08, 10:02 AM

1997 fzj80 with the stock inline 6cyl gas engine...all motor and drivetrain is stock...only mods include OME 3" lift and protection front and rear. vehicle only has 64,000 original miles...did have to have a new computer module installed by toyota when it had 10,000 miles on it.
as far as sounds go...there is a low rumble in low end of the engine when starting the vehicle...it is a small low rapping sound sometimes when full throttle...low end in the engine as well as in the low end of the sound spectrum
the other sound is when it is in the higher rpm's and under load towing up an incline and it sounds like a higher pitch from the top of the engine (it is not a heat shield or anything like that)...first thought it could be a lifter tap or something in the valves.
as far as the oil pressure...(don't have photos available)...but envision this...1/4 being the low indicator bar...1/2 being the mid bar...3/4 the higher bar...and 1 being the highest possible oil pressure reading...
at first i thought it could be lifter tap, maybe a rod (due to the oil pressure loss at higher rpms), or could it just need a oil and fuel system flush?
no mechanical issues at all except for maintenance and birfs....
i am an auto dealer and my techs still really can't diagnose...one says to perform the oil/fuel system flush and see what happens and the other says it is time for an overhaul...
tough dilemma...especially when trying to diagnose with my great descriptions!

Beowulf · 07-03-08, 11:22 AM

Quote:

Originally Posted by tetoncruiser

vehicle only has 64,000 original miles.

As you probably know, any Toyota engine with 64k miles is not your typical candidate for an engine rebuild. Possible, but rare.

If you are unsure of the history then look for signs of overheating or oil starvation. If you believe it has had neither then lets pursue what it could be that might explain the noises.

The OBD-II trucks can get some spark knock (aka "ping", or "clatter"). Try running some fuel additives and cleaner like Red Line or Techron. Run premium for a few tanks and see if that helps. Have the timing checked. If you are using the BIG Toyota filter then try the 90915-20004 filter. You can get them from Cruiserdan. Some trucks get a startup rattle and this is supposed to help.

The other noise might be belt tensioner or perhaps the belts themselves. Are you using Toyota belts?

-B-

tetoncruiser · 07-07-08, 10:37 AM

just had all the techs check the rig out...flushed the cooliing, system, oil change, checked for any possible signs of overheating/lack of oil, timing, plugs and everything are good...not just a piston slapping sound, looking like it is a piston...any thoughts on the next step? rebuild or just get new one?

AJP · 07-07-08, 12:04 PM

I imagine your techs have tried to isolate the source of the noise with a stethoscope...do you know where it is coming from?

tetoncruiser · 07-07-08, 01:55 PM

did not scope it but the sound is coming from piston 2 or piston 3

AJP · 07-07-08, 02:15 PM

Kind of an inexact science but if it is high in the block I would suspect a wrist pin .. if low .. a conn rod bearing or main... if louder and around the valve cover ... maybe a broken valve spring??

billmiranda · 07-14-08, 08:29 PM

You guys all make me nervous... I have 297k on my 1997 and haven't replaced anything...

07-02-08, 07:51 AM	#1
tetoncruiser IH8MUD Rookie Join Date: Jul 2008 Posts: 18	engine sounds/possible rebuild?? my 80 only has 65k miles and it is beginning to have a very minor low end sound (only during starting up) and another higher pitched cracking sound when towing and accelerating up hill when the engine is warmed up. oil pressure seems to be read 1/4 to 1/2 under acceleration. hoping it is not a rod....any thoughts???

07-03-08, 12:02 AM	#2
Beowulf The quick brown fox ..... Join Date: Mar 2003 Location: Somewhere in the foothills... Posts: 10,400	You should strive to give us more information. Which engine do you have? What year model? Can you be more specific on the sounds? It is virtually impossible to remotely diagnose a potential problem based on someone's verbal description of a sound so you will need to do a MUCH better job than a "low end sound". That doesn't tell us much. Low end of the sound spectrum? Low end as in the lower part of the engine? Also post a pic of the oil pressure gauge where you think it is a problem. A picture is worth a thousand words and your "1/4" might mean something completely different to me. Any history on the truck? -B- __________________ 97 FZJ80 - Wing Nut MAF, locked, 315 Toyos, 4.88s, Slee 4", George's sliders, Slee bumpers, M12000, OBA, Outback drawers + other stuff. Transformation in progress... Sometimes you find yourself in the middle of nowhere. And sometimes in the middle of nowhere, you find yourself.

07-03-08, 10:02 AM	#3
tetoncruiser IH8MUD Rookie Join Date: Jul 2008 Posts: 18	1997 fzj80 with the stock inline 6cyl gas engine...all motor and drivetrain is stock...only mods include OME 3" lift and protection front and rear. vehicle only has 64,000 original miles...did have to have a new computer module installed by toyota when it had 10,000 miles on it. as far as sounds go...there is a low rumble in low end of the engine when starting the vehicle...it is a small low rapping sound sometimes when full throttle...low end in the engine as well as in the low end of the sound spectrum the other sound is when it is in the higher rpm's and under load towing up an incline and it sounds like a higher pitch from the top of the engine (it is not a heat shield or anything like that)...first thought it could be a lifter tap or something in the valves. as far as the oil pressure...(don't have photos available)...but envision this...1/4 being the low indicator bar...1/2 being the mid bar...3/4 the higher bar...and 1 being the highest possible oil pressure reading... at first i thought it could be lifter tap, maybe a rod (due to the oil pressure loss at higher rpms), or could it just need a oil and fuel system flush? no mechanical issues at all except for maintenance and birfs.... i am an auto dealer and my techs still really can't diagnose...one says to perform the oil/fuel system flush and see what happens and the other says it is time for an overhaul... tough dilemma...especially when trying to diagnose with my great descriptions! __________________ 97 40th Anniversary, 3" OME, front ARB, PIAA's, rear Kaymar, Alpine system, Thule rack/carrier, 295 BFG's, stock locked

07-07-08, 10:37 AM	#5
tetoncruiser IH8MUD Rookie Join Date: Jul 2008 Posts: 18	just had all the techs check the rig out...flushed the cooliing, system, oil change, checked for any possible signs of overheating/lack of oil, timing, plugs and everything are good...not just a piston slapping sound, looking like it is a piston...any thoughts on the next step? rebuild or just get new one? __________________ 97 40th Anniversary, 3" OME, front ARB, PIAA's, rear Kaymar, Alpine system, Thule rack/carrier, 295 BFG's, stock locked

07-07-08, 01:55 PM	#7
tetoncruiser IH8MUD Rookie Join Date: Jul 2008 Posts: 18	did not scope it but the sound is coming from piston 2 or piston 3 __________________ 97 40th Anniversary, 3" OME, front ARB, PIAA's, rear Kaymar, Alpine system, Thule rack/carrier, 295 BFG's, stock locked

07-07-08, 12:04 PM	#6
AJP IH8MUD Regular Join Date: Oct 2005 Posts: 280	I imagine your techs have tried to isolate the source of the noise with a stethoscope...do you know where it is coming from?

07-07-08, 02:15 PM	#8
AJP IH8MUD Regular Join Date: Oct 2005 Posts: 280	Kind of an inexact science but if it is high in the block I would suspect a wrist pin .. if low .. a conn rod bearing or main... if louder and around the valve cover ... maybe a broken valve spring??

07-14-08, 08:29 PM	#9
billmiranda IH8MUD Junior Join Date: Jul 2003 Location: Northern VA TLCA# 7390 Posts: 99	You guys all make me nervous... I have 297k on my 1997 and haven't replaced anything... __________________ 91 80 Series: LT1, 6 inch Lift, SSRs, Custom Sliders, ARB Front Bumper. 97 80 series: 3" OME, Custom Bumpers&Sliders. Hand-throttle, 10k Winch, Scion radio, 35s, Slee xfer/Locker actuator armor. 90 4Runner SR5-V6: 2 inch OME Lift, 4.88s, Lockers, TSLs, Sliders, TJM Front, AllPro Rear, diff Armor.

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