I was replacing intake manifold gasket on my daughter's 2001 Toyota Celica. It's not a difficult job, but I ran into the center bolt on the intake manifold that was damaged (rounded and rusted).

I initially tried different socket sizes w/ no luck, both 6-pt and 12-pt.

The bolt was 8mm bolt size w/ original 12mm socket size, but a 11mm socket would turn easily over the bolt head.

I pulled my Craftsman rounded bolt sockets and tried sizes near 12mm w/o success. the bolt head was too shallow to allow the spiral knurls to engage the bolt head. It would simply rotate. I tried the smallest socket which initially appeared to be too small.

I tried using a cold chisel to "edge hit" and break loose w/o success.

About ready to cry "calf-roped" and reinstall parts leaving gasket in place, but decided to try my smallest rounded bolt socket again and drive it down onto the bolt head. This worked and socket engaged the bolt head, and I was able to loosen and remove the bolt.

I've been battling a persistent P0171 and have replaced MAF, O2 sensor, several large vacuum lines, and now intake manifold and throttle body gasket. After finishing today, I was severely disappointed to see LTFT stay at 27%, near what it was before replacing the gaskets. I wasn't totally surprised as the removed gaskets looked pliable and serviceable.

I plan to try a smoke test (see Scotty Kilmers cigar smoke method) to look again (already done once w/o finding any leaks) for intake air leaks.

Bottom line, everyone should have a set of these sockets. They are not used often, but are worth the cost (~$20-$30) when needed.

Sears.com

good luck

 

I also have the Sears ones. I bought them years ago. Good stuff.

 

A great way to find intake (and exhaust as well) leaks used by the General Aviation community is to use Duct Tape to seal the throttle body inlet, and then use more Duct Tape to secure a pressurized air hose into the exhaust pipe. Turn on the air supply and start spraying the engine with a bottle of soapy water; wherever there is a leak, you'll see air bubbles.

 

Thanks, I think I'll try that over the cigar smoke (makes me sick!).

regards

 

I tried the pressure test method w/o success. I spent 1/2 hr going over seams and joints looking for bubbles. I was only able to maintain a low pressure, perhaps 3-5 In-hg w/ a rubber glove over the intake duct.

I'm now planning to lift car on ramps to look for exhaust leak perhaps biasing the O2 sensor.

LTFT remains stubbornly high at 25-30%.

thanks

 

Hmmm, definitely sounds like a leak somewhere; good luck and keep us posted.

 

I tried pinching off vacuum supply lines to see if one of them affected LTFT and STFT. No changes when PCV, Brake Booster, and EVAP were pinched closed.

Replaced PCV under theory that perhaps old PCV spring was weak allowing too much PCV flow. No change after replacement.

I inspected exhaust pipe and found no leaks.

I'm going to try smoke test w/ cigar as my final test.

Right now I'm between rock and hard spot. I can't get a new TX title (car returned from my daughter after 3 yrs in FL) and TX requires Safety & Emissions inspections to get a title. I may have to scrap a pretty decent car (179K miles) which got 33 mpg driving from FL to TX. It needs some body work (dents, rash) and new paint to be a pretty sporty car.

I tried to get by emission inspection by resetting ECU and running car to complete emission checks w/o code appearance. However, by that time P0171 was pending and they would not pass.

regards