Anyone Had Engine Problems After Tsb Intake Gasket Change?

July 6, 2012

Evening all.

Going to have to ask for some help here - as i have run out of idea's....and my wallet is getting a bit desperate for a solution.........

Got the P0171 code a while back (along with P0300 & P0301), so read up, followed Toyota TSB EG046-07 and changed the manifold - engine block gasket.

Before the change, i was getting 450 - 460 miles to a tank, and the engine temp gauge reaching the last increment before the overheating marker once up to full operating temp......

Now (~6 tanks later) i am averaging 350 miles to a tank (for the same driving habits & conditions), and the temp gauge settles at the next increment down on the gauge when the engine has been running long enough to be at full operating temp.............

Since this gasket was changed, I have also noticed a bit of a rough idle, a persistant, yet intermittent 'fut-fut' noise in the exhaust note - cylinders misfiring?) and once she has been idling for 30 secs or longer, light timing chain noise seems to appear............( i don't know if these are related or not???).........

Over the past month i have changed/measured/cleaned/checked the following:

ECU error codes (none current, or pending)

All vacuum lines

All VSV's (that i can find)

Air filter + box

MAF sensor

Throttle body

IAC valve

TPS

ECT sensor

Thermostat

Chain tensioner

Spark plugs

Coils(for resisatnce)

Injectors (for resistance)

Compression tested each cylinder

Bled Coolant system

Cleaned and checked continuity of all earthing points (yielded minimal improvement of acceleration)

Pre & Post CAT 02 sensors (electrically for heater elements, and for cleanliness of sensor)

Exhaust system

All gasketted joints were closed with an additional coating of gasket sealant - as a belt and braces effort against any new leaks creeping in.

Despite all this, i have not seen any change.

I have not looked into fueling - as i have no experience of these systems, or any of the kit (Pressure gauge i'm guessing for one???) needed to work with them.

This issue asside, she is a great car to own and drive, and i REALLY don't want to let her go. Equally though, i am on the verge of giving up with her - as i now simply cannot afford to keep piling fuel into her at this rate, and i don't know where else to look / what else to try...........

Any and all help / suggestions (short of 'scrapyard') are welcomed with open arms at this point..........