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740 Did an oil change on my 740 and now theres a clicking sound. Is it piston slap?

89_740Turbo

89_740Turbo

New member
Joined
Apr 10, 2018
Location
Central New Jersey
I did an oil change on my 740 I picked up using Rotella 15w-50.

After the oil change, I started hearing a clicking sound coming from the engine. Additionally, some plastic scraps came from the old oil as I changed it. I heard that cold be the valve related? I dont know of this is piston slap and how concerned I should be.

Here is a video I took so you can hear it

ySAftkjTOKQ


https://youtu.be/ySAftkjTOKQ
 
If the plastic that you found in the drain pan looks like broken plastic rings it would be the valve hushers. My 88 765 has been making this noise for 13 years and hasn't gotten any worse.
 
lummert said:
If the plastic that you found in the drain pan looks like broken plastic rings it would be the valve hushers. My 88 765 has been making this noise for 13 years and hasn't gotten any worse.
Click to expand...

Ah, ok. Thank you for the peace of mind. Those little plastic bits were circular so that's probably what they were. I couldn't think of what they were when I saw them.

Is there a way to replace them or once they are gone they are gone for good.
 
89_740Turbo said:
Ah, ok. Thank you for the peace of mind. Those little plastic bits were circular so that's probably what they were. I couldn't think of what they were when I saw them.

Is there a way to replace them or once they are gone they are gone for good.
Click to expand...

You can but IMO it's really not worth it unless you're already taking the cam out for whatever reason. All they do is make the engine a bit less tractor-y.
 
89_740Turbo said:
Is there a way to replace them or once they are gone they are gone for good.
Click to expand...
Remove accessory drive belts.
Remove fan from water pump.
Remove main pulley.
Remove front timing covers.
Remove timing belt.
Remove valve cover.
Remove distributor from rear of head.
Remove camshaft.
Remove valve buckets.
Remove old hushers from valve stem tips.
Snap new hushers onto valve stem tips..
Put it all back together.

Complain that you wasted 3.6 hrs (Mitchell estimate). :rant:
Complain that there's new oil leaks. (Forgot to replace seals) :doh:
Complain that it doesn't run right. (Timing off a tooth, plugs wired mis-routed) :oops:
Throw a hissy fit :run: , crush it, and buy a rusty old Civic. :nono:


Pics from the InterWeb...

Old/New hushers.

ValveHusher1.gif


Husher on valve

ValveHusher2.gif


Cylinder head, 2 without, 2 with.

new_hushers.jpg
 
MasterBlaster said:
Remove accessory drive belts.
Remove fan from water pump.
Remove main pulley.
Remove front timing covers.
Remove timing belt.
Remove valve cover.
Remove distributor from rear of head.
Remove camshaft.
Remove valve buckets.
Remove old hushers from valve stem tips.
Snap new hushers onto valve stem tips..
Put it all back together.

Complain that you wasted 3.6 hrs (Mitchell estimate). :rant:
Complain that there's new oil leaks. (Forgot to replace seals) :doh:
Complain that it doesn't run right. (Timing off a tooth, plugs wired mis-routed) :oops:
Throw a hissy fit :run: , crush it, and buy a rusty old Civic. :nono:


Pics from the InterWeb...

Old/New hushers.

ValveHusher1.gif


Husher on valve

ValveHusher2.gif


Cylinder head, 2 without, 2 with.

new_hushers.jpg
Click to expand...

Thanks for the pictures. Gives me a good idea what to look for
 
Every used head I have pulled (which is not that many granted, maybe 8 or 9) none of them still had those valve hushers in there, they had all been sent into the oil pan hopefully. When I rebuilt heads (again not that many, I have built 5) I never use or install new ones. It doesn't make sense that the small plastic thing takes the heat and repeated beating of the cam kicking the **** out of it. When I rebuilt the heads and measured the lobe to lifter clearance it was fine without those things, they are just a good way to send plastic through your motor, which could potentially end up in a bad spot.
 
89_740Turbo said:
Ah ok. I'll just hold off for now then.

I was using 15w50 because of the weather but I went back to 10w30 tonight
Click to expand...

Oil is more viscous (more like molasses) when cold. Lower cold viscosity (the number before the W) is a little better for cold starts. In a B230, 10W-30 is fine year-round if you're driving around New Jersey.

15W-50 is a bit too viscous for cold weather cold starts.


Go to a library and look for an auto mechanics fundamentals textbook.
 
He ran that oil because it's what my 82 B21FT has used for many years. With synthetic the cold starting is fine. But I also suggested using the 5-40 rotella T6. That has great cold starting and is thicker than the 30w. Once these engines get over 100k I like the use a higher viscosity on the hot side like 40w. 10-40 is still an acceptable oil on the volvo oil chart.

Dem old hushers is dissolved away.
 
Rotella T6 5W-40 and and Rotella T3 15W-40 50/50 blend works fine in cold weather. Think of it as Heavy Duty 10W-40. If you need 7.5W-40 blend 5W-40 with 10W-40.
 
Clack clack sound goes away when the engine is warm? Sounds like an old Mercedes diesel when it's cold? That's piston slap.
 
As the owner of a piston slapping 740 turbo and also a 760 turbo with a similar sound to yours, I agree totally with Marvelous3's post. Piston-slapping is much more scary, but it goes away as the engine warms up. Your sound is coming from the valve train - too metallic for it to be an exhaust gasket leak, but hardly worth the trouble of the procedure described by MasterBlaster. Lummert's oil advice is good. As long as you use synthetic your engine will be fine. My 740 user manual recommends 15W-40. I used Chevron Delo 15W-40 synthetic blend in all my cars, and have no problems in the New York winter. Wait for warmer weather to address this, if you have to work outside.
 
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