Leaking valve guide seals? (1 Viewer)

How would you proceed if burning ~1 qt/500 miles?

  • Just buy more oil

    Votes: 4 17.4%
  • Replace valve guide seals, try to leave head on

    Votes: 2 8.7%
  • Pull head, have machine shop rebuild

    Votes: 13 56.5%
  • Full engine rebuild or new short block

    Votes: 2 8.7%
  • LS swap

    Votes: 2 8.7%
  • Use Barr's or similar

    Votes: 0 0.0%

  • Total voters
    23
Joined
Jun 26, 2004
Messages
1,876
Location
east coast Canada
 
 
 
I was not saying the tight valves cause oil burn. I was saying check valve clearances to Possibly eliminate Your low compression.

The bore that the bucket rides in is precision machined as is the bucket.

Attempting to do the valve seals with the cylinder head installed is a risky proposition.
 
Last edited:
Joined
Feb 5, 2009
Messages
34
Location
Knoxville, TN
 
 
/thanks/ to fj8ing for this one. lots of good intel i can see here. before i chunk through it i would like to ask:
1. nothing diagnostic to be learned from a oil sample analysis on this one from what i can gather?
2. how does the OP rule in or rule out rear main seal and/or oil pan arch seal leak?
THANKS
With worn rings there will be more blow-by, which will affect the oil. It would be even better if one has a history of test results (I do not).
My rear main and/or arch seal are leaking some, but it is only a drop every few weeks (I park in a garage over cardboard), not enough to account for the oil loss.

My conclusion on valve guide seals is somewhat an educated guess at this point, but the leak down test results were pretty good (from what I have read) with one cylinder a little worse that also had noticably higher leak out the intake.

Attempting to do the valve seals with the cylinder installed is a risky proposition.
After seeing everyone's replies on the head/valve design; I am definitely just pulling the head. Just ordered parts, including ARP studs. I have never been this excited by bolts!
 
Joined
Feb 5, 2009
Messages
34
Location
Knoxville, TN
 
 
Your oil burning Problem, if not low compression because of worn rings, is valve seals. To rule out low compression being worn rings you need to check valve clearances to make sure they are in spec. If out of spec and tight they will not seal giving an impression of worn cylinder rings.

Whew, that was a lot of typing for me 😳
Great point. I was underestimating the importance of checking the valve clearances but will certainly check them now before pulling the head.
 

fjc-man

SILVER Star
Joined
Mar 21, 2014
Messages
595
Location
Commerce City, Colorado
 
When head is being removed, once the valve cover is off, if you find a lot oily sludge built up. You should consider pulling a piston to check the condition of the rings. Compression and leakage test results are based mainly on the top two compression rings. The third ring is mostly shaving the oil off the cylinder wall, if it’s stuck it’s not doing much good at all. That’s why it’s called the oil control ring.
 
Joined
Feb 5, 2009
Messages
34
Location
Knoxville, TN
 
 
When head is being removed, once the valve cover is off, if you find a lot oily sludge built up. You should consider pulling a piston to check the condition of the rings. Compression and leakage test results are based mainly on the top two compression rings. The third ring is mostly shaving the oil off the cylinder wall, if it’s stuck it’s not doing much good at all. That’s why it’s called the oil control ring.
Another good thought, thank you. Seeing what's in the pan and a bottom bearing would be good too I would think.

I had the valve cover off about a year and a half ago (to replace a cheap-looking, leaking gasket installed by a previous owner). I apparently forgot to take pictures. I remember some build up on some surfaces, but don't remember it standing out specifically.
 
Joined
Oct 18, 2019
Messages
54
Location
Saudi Arabia
Hi guys,

I changed the valve seals in my 80 series 1FZ FE in the truck including cylinder 6 without pulling the engine or head.

We have made a video on youtube showing the process of changing the seals.


I hope this helps

If you guys do not mind please give me a thumps up on youtube and if you subscribe that would be great
 

wagonteeth

Hippoblanco
SILVER Star
Joined
Nov 18, 2008
Messages
568
Location
North GA mtns
 
 
I think that my leaking valve seals contributed to my timing chain breaking due to hydrolok. When I pulled the head, I had no signs of HG failure, but quite a bit of oil and ash on the pistons. Also quite a bit of smoke at start up. I was losing about the same amount of oil with no leak at the oil pump and only a few drops from the pan arch.

On the timing chain breaking, I drove to work that morning with no issues. At lunch I went to start it and got a pop and then the enging would just turn over without starting- no connection of the cams to the crank or dissy so no start.

Now that I have repaired it there is no smoke and no drips.
 
Joined
Dec 28, 2006
Messages
57
Location
I live in Flagstaff AZ
 
 
My white 1997 80 with 250k miles had a external weeping head gasket when I initiated a head rebuild. I sourced a discarded head from a bad engine and had a full rebuild done to it ($500). I then just did a complete head swap. I now have no oil loss with the engine. My second gold 1997 80 currently has 275k miles and burns oil slowly (smoke on startup) but with no indication of a failing head gasket. I plan to just do the valve seals on the motor like Doso shows in the video. I have one suggestion while you have your head on the bench. Consider blocking the exhaust thru head port for the EGR system. I accomplished it by tapping it and using a NPT allen head plug. Assuming you live in a no smog check area.
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Joined
Feb 5, 2009
Messages
34
Location
Knoxville, TN
 
 
Finally got the head off. Head gasket looked good. Cylinders looked pretty good. Definitely burning oil.

Just heard from the machine shop. Head was in good shape. Valve guide seals were indeed shot. He took off very little to true it up (I think he said less than 0.001”)

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I am not sure what I will do with EGR yet. I removed PAIR a while ago.

Lifted the head off without help. It is heavy and awkward, not doing that again!
 
Joined
Feb 5, 2009
Messages
34
Location
Knoxville, TN
 
 
Hi guys,

I changed the valve seals in my 80 series 1FZ FE in the truck including cylinder 6 without pulling the engine or head.

We have made a video on youtube showing the process of changing the seals.


I hope this helps

If you guys do not mind please give me a thumps up on youtube and if you subscribe that would be great
Video was great, clever approach!
 

ppc

M Go Blue
Joined
Aug 18, 2003
Messages
3,216
Location
Nashville, TN
 
 
 
Not a good idea to put weight on the top tank of the radiator as shown in the above picture. That can damage/loosen the seal between the top tank and core.
 
Joined
Feb 5, 2009
Messages
34
Location
Knoxville, TN
 
 
Not a good idea to put weight on the top tank of the radiator as shown in the above picture. That can damage/loosen the seal between the top tank and core.
Good point. Every comment I've seen on lifting off the head says have a hoist or two people. I can confirm the validity of their suggestions.

Head is back, but our second child was just born 7 weeks early, so work paused at the moment. (Mom and baby are doing well 🙂)
PXL_20201126_224520602.jpg
 

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