The above vehicle came from a quick lube shop . The oil filter housing cracked and it leaked out 3 quarts of oil. After it was fixed it had a terrible surge and a P0340 code. The code can be deceiving as with many manufactures its more of a correlation code in this case.

I looked at the waveform and cleared the code only to have symptom and code quickly return.

ECM/Inputs/Outputs Waveform

I found a known good waveform and knew what the next step was. To do this job properly you are removing the front cover. Or you can make this hack tool and whip in about an hour.

You take this SK 6 point wrench part # 88365 and have it milled to 3.7 mm and weld a nut to it that allows you to attach a socket.

Wrench milled

There is a tool that screws in the back of the block for TDC that I have but the axle will have to come out. I usually use a vacuum gauge and a screw driver to find TDC #1. I will then steal a bolt form the timing cover and screw in through the balancer and into the cover like so.

Mazda TDC with bolt stolen from cover

With piston on TDC and the valve cover removed you can see the intake cam off.

Cam off

You loosen the Intake cam bolt with special wrench and the exhaust with a crows-foot wrench. You then use a wrench , sorry don't remember the size 1 1/8 inch maybe and rotate the cam until the flat stock bar lines up the cam slots in the back of the cam.

Here is the intake cam sprocket being torqued to spec , actually a few ft lbs more due to the leverage of the butchered wrench =)

Photo

Here is the exhaust cam sprocket being torqued with the crows foot wrench.

Crowsfoot

When that is done the vehicle is started , surge is gone, code is gone, and the waveform looks good.

ECM/Inputs/Outputs Waveform

Not to derail this too much but a very similar thing can easily be done when someone does a front seal and gets timing off by rotating cams to allow the crank to be moved. That is a whole other story.

I know this isn't the right way to do this but it does work and has a place in your arsenal. This case the oil change place tried to bail , the car was rough, customer was pissed , and in 1 hour its business as usually.

To date I have done 4 of these with one being on the road 22k miles and its still fine.

They say the chain stretches when run low on oil I believe the cam gets tight in the head and moves. I'm probably wrong as usual all I know is this keeps the vehicle, customer, and mostly me happy =)

PS this tool only works on the 2 wire cam and crank sensors. The 3 wire hall effect sensors have an 18mm bolt and I have yet to make that tool .

Mike from Ohio

Files Referenced: