T100 leaky valves and check engine light

so I just got bought a 1997 T100 V6 4x4, with 109k on it. Got it for $5900 knowing I would need a 90k mile maintenance and all belts replaced. Also the check engine light it on so have to have that fixed to even try to get it smogged.

ive got leaking valves dripping oil onto exhaust. Could led this be causing the check engine to come on? Also, how bad is this leak for the wallet?

Thanks for the advice!

 

Can you pull the code? No way of knowing what the CEL is for without knowing the code. You can take it to any auto parts store and they'll read it for free (unless you live in Commiefornia)

 

Leaky valve covers are common for these engines. Here's a complete step by step how to video. I bought Amazon gaskets since it's not holding high pressure contact points. Super easy to do. Even with oem gaskets it's not too expensive.



If you're talking about leaking valves like you have a leaking valve guide, I'd replace the engine rather than go through a whole head gasket / head repair, but I think you meant your valve cover is leaking on to the exhaust manifold.

If you're talking about the valve cover, it's not going to cause any CEL's (except what Clearwater Bill mentioned below) - only if you're losing enough oil to run low on it which is unlikely since not that much makes it that high up in the engine to leak out quickly.

 

Once you get that worked out you should jump on this deal.

https://www.tacomaworld.com/threads...or-1986-1995-4runner-pick-up-and-t100.503132/

 

Do the gaskets as part of your 90k services, while things are disassembled anyway.

Gaskets should not impact CEL, unless the CEL is misfire related because the plug wires are saturated.

 

If enough oil is getting downstream of the exhaust manifold or it just been leaking long enough that could be guming up you O2 sensors no?

 

Valve covers should be external leaks onto the outside of the manifold and burn off very quickly.

The sensor head that fouls is internal to the exhaust stream.

 

ah yes, I see now. I read valve seals, not valve cover seal.