2004 Toyota Tacoma Excessive engine blow-by

TOON

MEMBER
2004 TOYOTA TACOMA
4 CYL
2WD
AUTOMATIC
57,000 MILES

Excessive Blow-by in 2.7 L
I have a 2004 Tacoma PreRunner 4x2 with a 2.7 L engine and 57k miles. It seems to lack power so I did a compression check which turned out OK, but when I did a leak down test, it had 50% leakage in each cylinder. I could hear air leaking from the oil fill hole in the valve cover. I couldn’t hear any leakage in the exhaust pipe or the intake manifold. When I take the oil fill cap off while the engine is running (hot or cold), air blows out. So much blows out that an oil mist sprays out and I can feel the air (and droplets of oil) from 2' above the hole. I have replaced the PCV valve and that didn’t help. The warranty expires on the power train soon.
Thanks in advance for any help!

1 Reply

RACEFAN966

MECHANIC
5,029 POSTS

If it is still under warranty you need to get in and checked out. It sounds like you may have a head problem. Worn valve guides or valve guide seals. As for the oil spraying out of the valve cover this is normal as the rockers will splash it everywhere so this don't realy bother me but the leak down test does. So get it in before the warranty expires, If you do any thing like start tear down or attempt to do the fix yourself then warranty is void. Hope this helps and have a great day.