Tappet cover freeze plugs - Competition Diesel.Com

syrupdawg · 12-21-2014, 06:29 PM

How many times has anybody saw one of the tappet cover freeze plugs come loose? I'm getting some water in the oil of a freshly built 12 valve. It put a pretty good bit of water in the oil in probably 20 mins of idle and free revving. A few of those included some 5000 rpm blasts but no load on it at all. Its not getting oil in the water so that would mean its a low oil pressure part of the engine. Really hoping its not a cracked head or block.

stubz616 · 12-21-2014, 06:32 PM

I've seen a few afternarket freeze plugs come loose. None behind the tappet cover but on the side of the block under the manifold. I was told by another member, I forget who now, that if the factory freeze plugs are changed out they are much more likely to come loose. I always install freeze plugs with some silicone/RTV sealant on them to help them seal and stay in place.

syrupdawg · 12-21-2014, 06:40 PM

Quote:

Originally Posted by stubz616

I've seen a few afternarket freeze plugs come loose. None behind the tappet cover but on the side of the block under the manifold. I was told by another member, I forget who now, that if the factory freeze plugs are changed out they are much more likely to come loose. I always install freeze plugs with some silicone/RTV sealant on them to help them seal and stay in place.

These are the factory plugs behind the tappet cover. The ones on the side of the block are billet.

stubz616 · 12-21-2014, 06:41 PM

Quote:

Originally Posted by syrupdawg

These are the factory plugs behind the tappet cover. The ones on the side of the block are billet.

As in they were never removed? That's what I meant when I said factory

syrupdawg · 12-21-2014, 06:43 PM

Quote:

Originally Posted by stubz616

As in they were never removed? That's what I meant when I said factory

Correct the ones behind the tappet cover have never been removed to my knowledge

stubz616 · 12-21-2014, 06:45 PM

You could remove a pushrod and go in with a borecam and pressurize the cooling system with a pressure test tool and see if one is leaking. That's the best/easiest option short of pulling the pump and tappet cover off

stubz616 · 12-21-2014, 06:47 PM

If I were ever to do a full rebuild, I would remove those plugs and drill/tap the holes to a NPT and install threaded plugs in their place

syrupdawg · 12-21-2014, 06:49 PM

Quote:

Originally Posted by stubz616

If I were ever to do a full rebuild, I would remove those plugs and drill/tap the holes to a NPT and install threaded plugs in their place

Pulling the pump and tappet cover won't take long...I'm planning on doing that tomorrow and pressurizing the coolant system to see what's going on. I'm just sitting here trying to diagnose it in my head

stubz616 · 12-21-2014, 06:51 PM

It's gotta be those, head gasket, or oil cooler

syrupdawg · 12-21-2014, 06:55 PM

Quote:

Originally Posted by stubz616

It's gotta be those, head gasket, or oil cooler

I've ruled out oil cooler...oil pressure is greater than water and it never sat there with water in it not running

CorneliusRox · 12-22-2014, 08:02 AM

You didn't try using a MLS Common Rail head gasket on a 12V did you? This will happen. Just a thought.

syrupdawg · 12-22-2014, 09:09 AM

Head is cracked on number 5 exhaust valve.

97rada · 12-22-2014, 10:09 AM

That's never fun, I take it most people don't tap those plugs behind the tappet cover? I am curious what size you can tap them out to for plugs

12-21-2014, 06:29 PM	#1
syrupdawg Name: syrupdawg Title: GA Diesel Mafia Status: Not Here Join Date: Mar 2008 Location: Cairo, GA Member`s Gallery Posts: 1,792	Tappet cover freeze plugs How many times has anybody saw one of the tappet cover freeze plugs come loose? I'm getting some water in the oil of a freshly built 12 valve. It put a pretty good bit of water in the oil in probably 20 mins of idle and free revving. A few of those included some 5000 rpm blasts but no load on it at all. Its not getting oil in the water so that would mean its a low oil pressure part of the engine. Really hoping its not a cracked head or block. __________________ Motor boatin'

12-21-2014, 06:32 PM	#2
stubz616 Name: stubz616 Title: Too Much Time Status: Not Here Join Date: Oct 2008 Location: Brewster, MA Member`s Gallery Posts: 1,327	I've seen a few afternarket freeze plugs come loose. None behind the tappet cover but on the side of the block under the manifold. I was told by another member, I forget who now, that if the factory freeze plugs are changed out they are much more likely to come loose. I always install freeze plugs with some silicone/RTV sealant on them to help them seal and stay in place. __________________ 95 RCLB Farrell Diesel Stage 5 13mm pump,Hamilton Springs,Retainers,Pushrods,Fluidampr,Steed Speed,S467.7/soon to be S488 atmo,Full Billet Trans,DPC 4 disk TC,BD Pressure Loc,Haley Speed 5x.022s,Diesel Pros Custom Cam,O-Ringed,.010 over HG,A1000,Hellman sump,625 Studs, 30*

12-21-2014, 06:45 PM	#6
stubz616 Name: stubz616 Title: Too Much Time Status: Not Here Join Date: Oct 2008 Location: Brewster, MA Member`s Gallery Posts: 1,327	You could remove a pushrod and go in with a borecam and pressurize the cooling system with a pressure test tool and see if one is leaking. That's the best/easiest option short of pulling the pump and tappet cover off __________________ 95 RCLB Farrell Diesel Stage 5 13mm pump,Hamilton Springs,Retainers,Pushrods,Fluidampr,Steed Speed,S467.7/soon to be S488 atmo,Full Billet Trans,DPC 4 disk TC,BD Pressure Loc,Haley Speed 5x.022s,Diesel Pros Custom Cam,O-Ringed,.010 over HG,A1000,Hellman sump,625 Studs, 30*

12-21-2014, 06:47 PM	#7
stubz616 Name: stubz616 Title: Too Much Time Status: Not Here Join Date: Oct 2008 Location: Brewster, MA Member`s Gallery Posts: 1,327	If I were ever to do a full rebuild, I would remove those plugs and drill/tap the holes to a NPT and install threaded plugs in their place __________________ 95 RCLB Farrell Diesel Stage 5 13mm pump,Hamilton Springs,Retainers,Pushrods,Fluidampr,Steed Speed,S467.7/soon to be S488 atmo,Full Billet Trans,DPC 4 disk TC,BD Pressure Loc,Haley Speed 5x.022s,Diesel Pros Custom Cam,O-Ringed,.010 over HG,A1000,Hellman sump,625 Studs, 30*

12-21-2014, 06:51 PM	#9
stubz616 Name: stubz616 Title: Too Much Time Status: Not Here Join Date: Oct 2008 Location: Brewster, MA Member`s Gallery Posts: 1,327	It's gotta be those, head gasket, or oil cooler __________________ 95 RCLB Farrell Diesel Stage 5 13mm pump,Hamilton Springs,Retainers,Pushrods,Fluidampr,Steed Speed,S467.7/soon to be S488 atmo,Full Billet Trans,DPC 4 disk TC,BD Pressure Loc,Haley Speed 5x.022s,Diesel Pros Custom Cam,O-Ringed,.010 over HG,A1000,Hellman sump,625 Studs, 30*

12-22-2014, 08:02 AM	#11
CorneliusRox Name: CorneliusRox Title: Seasoned Rookie Status: Not Here Join Date: Dec 2012 Location: Detroit, MI Member`s Gallery Posts: 4,154	You didn't try using a MLS Common Rail head gasket on a 12V did you? This will happen. Just a thought. __________________ Corey - BSME '21 Tesla Model 3 Perf '22 DMax AT4 2500

12-22-2014, 09:09 AM	#12
syrupdawg Name: syrupdawg Title: GA Diesel Mafia Status: Not Here Join Date: Mar 2008 Location: Cairo, GA Member`s Gallery Posts: 1,792	Head is cracked on number 5 exhaust valve. __________________ Motor boatin'

12-22-2014, 10:09 AM	#13
97rada Name: 97rada Title: Too Much Time Status: Not Here Join Date: Feb 2008 Member`s Gallery Posts: 5,410	Tappet cover freeze plugs That's never fun, I take it most people don't tap those plugs behind the tappet cover? I am curious what size you can tap them out to for plugs __________________ Austin tow truck- 14-3500 with tuning toy truck -94 rclb auto- 5.2x with a lot left. Shooting for 4s Any intelligent fool can make things bigger and more complex...it takes a touch of genius- and alot of courage to move in the opposite direction.