Bubbling oil in engine? (1 Viewer)

[Kawabunga]

A little intro since i'm new here, recently purchased a 97 LX 450 with 244K mi. so knew I probably had some work to do. body is in great shape, very little rust except on the rearend area but not bad, looks like a boat might have been towed with it. Interior also in great shape except for the front seats, engine is pretty clean except for the usual oil underneath. Several days after picking it up the alternator goes so change it last weekend then a day after that the radiator starts leaking, I knew there would be some work but not all in the first couple weeks ha ha.

Planning on maybe adding a small lift, tires, and armor. Will mainly be used for hunting and fishing on the weekends. My son calls it the "Cruisinator"

So on to the weird noise. When I start it up cold theres a bubbling sound coming from the engine, sounds like its coming from the rear of the engine but when I open the oil fill it's really loud in there and i'm pretty sure its the oil or it really sounds like it is. The thing is when it warms up it goes away completely. I've done searches but only found references to water, or power steering I swear it's in the crankcase. The oil is clean and it runs smooth, no bubbling in the radiator or anything, I haven't checked all the plugs yet or compression, planning to do that this weekend maybe.

Thanks in advance for any help, and for this great community, really impressed with this forum.

 

[mjosoba]

Usually it’ll be the mix valve on the firewall. How’s your heat? Mine is new and still does it on occasion, after it’s been sitting for a long weekend. I’m may have a bit of air left in the system or something. Not too sure.

 

[KC masterpiece]

How long does it last after a cold start? Could be timing chain rattle.

Strange my cruiser will not run if the oil fill cap is open. Chokes the engine out immediately.

 

[BILT4ME]

A little intro since i'm new here, recently purchased a 97 LX 450 with 244K mi. so knew I probably had some work to do. body is in great shape, very little rust except on the rearend area but not bad, looks like a boat might have been towed with it. Interior also in great shape except for the front seats, engine is pretty clean except for the usual oil underneath. Several days after picking it up the alternator goes so change it last weekend then a day after that the radiator starts leaking, I knew there would be some work but not all in the first couple weeks ha ha.

Planning on maybe adding a small lift, tires, and armor. Will mainly be used for hunting and fishing on the weekends. My son calls it the "Cruisinator" View attachment 2258582

So on to the weird noise. When I start it up cold theres a bubbling sound coming from the engine, sounds like its coming from the rear of the engine but when I open the oil fill it's really loud in there and i'm pretty sure its the oil or it really sounds like it is. The thing is when it warms up it goes away completely. I've done searches but only found references to water, or power steering I swear it's in the crankcase. The oil is clean and it runs smooth, no bubbling in the radiator or anything, I haven't checked all the plugs yet or compression, planning to do that this weekend maybe.

Thanks in advance for any help, and for this great community, really impressed with this forum.

Can you post a link to a video of the noise you're hearing?

The engine SHOULD have oil "bubbling" in it. What you're more likely hearing is an air bubble in the cooling system and you hear it because the heater is in the cab with you.

However, if you are not skilled in the use of the terms of bump, knock, rattle, bang, clang, whoosh, swish, gurgle, and pop, then you may need further assistance here. I am actually being serious, as each of these terms has a different sound and diagnosis associated with the sounds.

 

[Kawabunga]

Can you post a link to a video of the noise you're hearing?

The engine SHOULD have oil "bubbling" in it. What you're more likely hearing is an air bubble in the cooling system and you hear it because the heater is in the cab with you.

However, if you are not skilled in the use of the terms of bump, knock, rattle, bang, clang, whoosh, swish, gurgle, and pop, then you may need further assistance here. I am actually being serious, as each of these terms has a different sound and diagnosis associated with the sounds.

Thanks for the replies. Familiar with some of those terms ha ha, my last project was a 69 Camaro which I sold a few years ago, my only non Toyota project vehicle, had some 22Rs, Old Celica, 3.4 4 Runner and have an 02 Tundra so think i'm a decent backyard mechanic.

I'll use the term "gurgle" as it's definitely a liquid bubbling pretty much like boiling water. Also it's not from the cab its with the hood open, standing in front of the truck, when I open the oil fill you can hear it especially if you put your ear closer. My first thought is what you said about oil moving but this sounds like air bubbles and it completely goes away when the engine warms up so the cooling system makes sense since it circulates through the block and head, just weird how loud it is in there.

How long does it last after a cold start? Could be timing chain rattle.

Strange my cruiser will not run if the oil fill cap is open. Chokes the engine out immediately.

To answer KCs question I would say it goes away after normal warm up time from a cold start however long that is, few minutes maybe little more.
Haven't tried the heater yet but will play with it and see if it makes a difference. Debating wether or not to delete the rear heater as I rarely use heat here maybe a few times in the winter hunting up high and would still only need the front anyway.

Also changing out my radiator this weekend, along with hoses and oil cover / crank seals if my parts come in so ill be flushing the system, hopefully its just air in there.

I'll try to get a vid of it and post, thanks again for the replies.

 

[BILT4ME]

Thanks for the replies. Familiar with some of those terms ha ha, my last project was a 69 Camaro which I sold a few years ago, my only non Toyota project vehicle, had some 22Rs, Old Celica, 3.4 4 Runner and have an 02 Tundra so think i'm a decent backyard mechanic.

I'll use the term "gurgle" as it's definitely a liquid bubbling pretty much like boiling water. Also it's not from the cab its with the hood open, standing in front of the truck, when I open the oil fill you can hear it especially if you put your ear closer. My first thought is what you said about oil moving but this sounds like air bubbles and it completely goes away when the engine warms up so the cooling system makes sense since it circulates through the block and head, just weird how loud it is in there.







To answer KCs question I would say it goes away after normal warm up time from a cold start however long that is, few minutes maybe little more.
Haven't tried the heater yet but will play with it and see if it makes a difference. Debating wether or not to delete the rear heater as I rarely use heat here maybe a few times in the winter hunting up high and would still only need the front anyway.

Also changing out my radiator this weekend, along with hoses and oil cover / crank seals if my parts come in so ill be flushing the system, hopefully its just air in there.

I'll try to get a vid of it and post, thanks again for the replies.

Good to know!

When you remove the oil fill cap, does the engine start to sputter! It should, unless you have many existing vacuum leaks and the computer is already compensating.

It is also likely that you're hearing a timing chain sort of loose in the case until the oil pressure builds enough to adjust the chain tensioner.
Maybe try a different weight engine oil to see if it affects the rate you hear the noise.

Also check the torque on the harmonic balancer to 304 LB-FT, as that is what drives the oil pump and power steering pump and is a critical torque.

 

[Kawabunga]

Good to know!

When you remove the oil fill cap, does the engine start to sputter! It should, unless you have many existing vacuum leaks and the computer is already compensating.

It is also likely that you're hearing a timing chain sort of loose in the case until the oil pressure builds enough to adjust the chain tensioner.
Maybe try a different weight engine oil to see if it affects the rate you hear the noise.

Also check the torque on the harmonic balancer to 304 LB-FT, as that is what drives the oil pump and power steering pump and is a critical torque.

Thanks! great info, no the engine does not react when the cap is removed guess another thing I need to check. Familiar with the timing chain rattle as those old 20-22rs would rattle like hell at start up, we still have a couple late 80s early 90s at work that still run and thinking about it the guy gave me a gallon of 10-40W that he said he's been using, needs to be changed anyway. I gotta figure out where to get a torque wrench that goes up that high, our mechanic has a Snap On but only goes to 200lbs.

Thanks again for the suggestions i'll keep you guys posted.

 

[Kawabunga]

Heres a short vid, shoulve kept the camera pointed at the fill, you can hear it better. Lot's of other sounds in the vid, think I do hear maybe some chain in there but off camera the bubbling is much more prominent. Also the noise stops, may still be there but barely when the engine warms up and the idle drops if this may be an indicator of something. I also had the hose clamp off the vac hose to the valve cover, was checking hoses for cracks, found a couple old stiff ones that look suspect.

 

[BILT4ME]

Heres a short vid, shoulve kept the camera pointed at the fill, you can hear it better. Lot's of other sounds in the vid, think I do hear maybe some chain in there but off camera the bubbling is much more prominent. Also the noise stops, may still be there but barely when the engine warms up and the idle drops if this may be an indicator of something. I also had the hose clamp off the vac hose to the valve cover, was checking hoses for cracks, found a couple old stiff ones that look suspect.

That could be the chain tensioner is remaining loose until it is up to temp and the oil pressure builds enough. You're hearing the chain in the oil bath at the bottom of the sump around the crankshaft. That's what the gurgling sound is.

Most of these engines barely run when you remove the oil fill cap because of the horrendous "vacuum leak" that creates.

That tells me you have a LOT of vacuum leaks and your ECU has learned to compensate.

Do early oil changes to clean up your lubrication system. Some here use Rotella diesel oil because it has more cleaning agents and may help take care of things. Don't use Seafoam, as that reduces oil viscosity and will also release a bunch of crud into the system all at once and overload filters, rings, other things, and typically does more damage than good.

Only run Toyota oil filters, as Wix and Napa oil filters have been shown in recent years to have a serious failure rate causing oil pressure starvation.

Eventually, you need to pull the EFI fuse for one minute to clear all ECU codes and clear the data. Then when it restarts, it will run wonky for a bit, then start to relearn after you've done some of the work. If you do it before, it won't like all the leaks and stuff until it relearns and that won't be pleasant.

 

[Kawabunga]

That could be the chain tensioner is remaining loose until it is up to temp and the oil pressure builds enough. You're hearing the chain in the oil bath at the bottom of the sump around the crankshaft. That's what the gurgling sound is.

Most of these engines barely run when you remove the oil fill cap because of the horrendous "vacuum leak" that creates.

That tells me you have a LOT of vacuum leaks and your ECU has learned to compensate.

Do early oil changes to clean up your lubrication system. Some here use Rotella diesel oil because it has more cleaning agents and may help take care of things. Don't use Seafoam, as that reduces oil viscosity and will also release a bunch of crud into the system all at once and overload filters, rings, other things, and typically does more damage than good.

Only run Toyota oil filters, as Wix and Napa oil filters have been shown in recent years to have a serious failure rate causing oil pressure starvation.

Eventually, you need to pull the EFI fuse for one minute to clear all ECU codes and clear the data. Then when it restarts, it will run wonky for a bit, then start to relearn after you've done some of the work. If you do it before, it won't like all the leaks and stuff until it relearns and that won't be pleasant.

Timing chain makes sense, I’ll try those things. Used to run Rotella in the Camaro.

this weekend I pulled the PCV hose of the intake and it died immediately, so lots of vacuum, plugged PCV? Gonna get a new one, figure it has to be plugged allowing the engine to run with the cap open and that much vacuum in the hose.
Thanks again for the great info!

 

[Kawabunga]

So played around with the PCV, changed the bushing and cleaned it up, seems to be working fine. I can pull the PCV out and it still doesn't die or miss a beat but when I pull it off from the intake side it wants to die so I guess with the PCV on its enough of a restriction to keep it running. Tried looking for any leaks, but couldn't find anything and the engine runs great so not letting it bother me.

Still have the bubbling sound till warmup, all new oil, maybe ill play with the
EGR one day, wouldn't mind deleting it too.