348 Phase sensor replacement.

No issues with the phase sensor but it is nearly 30 years old so a bit of preventative maintenance. MY1991...Recommended to remove air box for better access.
Located in a housing on the back of the 1-4 cylinder bank inlet camshaft. There is an electrical connector and alloy clamp to disconnect shown on the LHS. Clamp held by a 8mm nut. Housing held by 3 10mm nuts.

Image Unavailable, Please Login

Housing and sensor removed. Wiring harness and clamp shown.

Image Unavailable, Please Login

Housing removed showing timing disc attached to camshaft.

Image Unavailable, Please Login

Timing disk attached with three screws and mounted on a locating dowel so you can't get this wrong.

Image Unavailable, Please Login

Image Unavailable, Please Login

Check for oil ingression into the housing and if present replace the rear cam seal visible in the picture. To do this you will have to remove the inner housing as well. The three Allen bolts that are visible. There is a gasket between the housing and head you will be wise to replace too. This one is oil free.

Image Unavailable, Please Login

New sensor and timing wheel.

Image Unavailable, Please Login

Fitted to housing. Secured by the two small Allen bolts shown on the right.

Image Unavailable, Please Login



Image Unavailable, Please Login

Refit housing etc. Easy DIY..

 

Thanks, Nick. Bookmarked!

Maybe we could have this one put in the sticky threads?

 

Nice job!

Thanks for sharing.

 

Nice job

 

I secretly smile on the idea of changing parts on Ferrari when nothing is actually broken (it puts food on my family table!). However if there were zero fault indications from your existing phase sensor, why did you chose to install a new one?

In my mind, the real issue would have been evidence of oil seepage from the lip seal behind that housing, 149917 or the paper gasket 150076. It looks perfectly dry in your photos. Right?

 

I have stated why in my first sentence. Just part of my process. Smile on..

 

Yes, really. If you are worried about parts that are 30 years old you need to start replaced a lot more than the phase sensor.

 

Well, there are two choices: preventive maintenance and breakdown maintenance. I prefer the first one. The cam sensor is a Hall Effect transistor (not just a simple coil like the crank sensors) and can go without warning.

 

I have done. I must be totally insane.

 

Great question, 2 reasons:
1) Consumable parts are old and have a shelf life. Like check valves for fuel venting, why wait for them to fail and fuel tank to crumple before going damn, I should have replaced them. Same for water temp and fan and oil temp switches, most things like that are cheap and consumable and prevent you from being stuck 300 miles from home in limp mode. I replaced every relay on my car, man they were old and corroded the inside could not be amazing. Hell I have a 2 page single spaced list of replacement things I'm working through, you have lots of my money already. Believe it or not simply replacing my actual window switches with NEW ones made the biggest difference in window speed. Those window accelerators did first did little. Go figure. Switches..... Stuff is old and almost all consumable parts simply work better new. DIY makes it affordable.

2) Its a project for many some of us like working on it and obsess about stupid things, its part of the fun. Every post where someone has a problem part that caused an issue wind up on my replace before failure list. Side mirror switch went bad prevented mirror working one post outlined, I found a new one, put it in, my mirror won't go bad for that reason and I have my original one as a spare.

I'm sure you get my orders and scratch your head "why the hell would any one replace the air injection check valve" or IAC valves. Yeah I don't know either but I know I wont break down because of them and I idle amazing.

 

In the last couple of years on the engine control and running side of things Ive replaced the below. Mainly preventative.

Ignition coils.
Ignition power modules.
Throttle position sensors.
Two Lambdas at different times. (faulty)
Phase sensor.
Both crank sensors.
All relays due to a couple of failures of originals..
Air injection check valves. Old and rusty.
Cooling fan switch.
Temperature sensors.

Even had an Motronic 2.7 ECU go bad last year. A horrible intermittent fault throwing up a strange array of irrelevant and confusing fault codes.. Now repaired. Thats another story.

Being a lifelong tech I do my own servicing and diagnostics so no labour.. 500-600 USD for all that is a no brainer. 95% genuine Bosch parts too.
Ive seen all the above fail multible times on other marques as well as Ferrari so no issues with swapping out any of it. Piece of mind.
We all see and do things in our own way. Car runs better than ever and I feel is reliable which is the whole point.
OCD ? Yes,probably.

The story so far. showthread.php

 

That sensor, and the 355 one, suffers from high heat in the cabin. I have replaced a few of those where the connector portion of the sensor severely cracks and exposes inside wiring. The 348 one wasn't too bad but the 355 was an arm and a leg. Not a bad job.

 

If you don't mind a bit of soldering, you can actually replace just the "head" of the cam sensor. It is Siemens HKZ101 which is cross referenced, to name just a few, to ZD1900 and CYHME301 by other manufacturers. There are also many Chinese equivalents to the Siemens HKZ101 at just $16 (https://www.ebay.com/itm/1pcs-HALL-PICK-UP-SENSOR-HME101-compatible-HKZ121-HKZ101-HKZ101E-HKZ101S/264279998707?hash=item3d8850c0f3:g:t7wAAOSwfpVZH9sv). This type of sensor (Hall Effect) is also used on Volvos (p/n 1346792-3) the equivalents of which are HUECO 138152, FACET 8.2722, BREMI 16522, INTERMOTOR 14011 and many other.

I bought one (for spare) by "Vemo" (https://www.ebay.com/itm/Ignition-Pulse-Sensor-Fits-VOLVO-740-760-940-Sedan-Wagon-2-0-2-3L-1984-1993/332083502089?fits=Make%3AVolvo&hash=item4d51b81c09:g:QNgAAOSwwmlcXLna) as I preferred something better than the Chinese knock-offs.

 

I was told about the connectors breaking up years ago by a fellow owner. It does get very hot in there. Sensor was around 100 USD. Ive seen them cheaper on eBay from time to time.