When one of the timing chains started rattling, discovered the culprit was not the known defective chains, tensioners and guides -- replaced those years ago -- but the intake VVT unit and solenoid. Seems to be one unit? Thinking better to replace all anyway?

Looking for an alternative supplier to Jag which wants about $600 a unit or more for intake sprocket, phaser and solenoid.

Any suggestions? Would the VVT unit for a 4.2 liter V-8 fit the 4.0?

I believe the parts number for the 4 liter is LCA 1535AD? Maybe only through some VINs?

Would Ford be a source since the 4.0 liter was used in Lincoln LS models, too?

Coventry West has used ones with six month warranties. Any experience?

Lots of questions. All advice welcome!

Thank you.

 

I'm pretty sure that the 4.2 engine has the "multi-row" Morse-type chain, and therefore the CVVTs are non-interchangable.

There were two types of variable valve timing units, the early AJ26 series were two stage and therefore Variable Valve Timing (VVT), the later AJ27 engines had Continuously Variable Valve Timing (CVVT), so you would require the later type for your 2001 model year.

I think the Jaguar part number is AJ84066

As these units rarely fail, I would think that a recycling yard may be your best bet.

(And as a side note, which you probably already know, the SC version of the engines do not have CVVT, so those units are not suitable for your vehicle).

 

The AJ27 or AJ28 units would work.
I'm sure there are lots of scrap heads with good intake cam VVT units and actuators.
I probably have a half dozen in boxes from scrapped engines.

 

Thanks, Carnival How do I know for sure whether I have an AJ 126 or AJ 127? My VIN is ends in LF30061 Build in 12/2000, that helps,

 

Motorcarman,

Is it your considerable experience that a used unit is probably fine? My solenoids didnt fail. the sprocket phaser did?

Do you know if have a low mileage A127 or A128? Coventry West has some but doesnt know mileage.

Thanks

 

The AJ27 was in the NA Jags from year 1999 so you certainly have an AJ27 engine, CVVT p/n NNE2016AB. The AJ26 VVT and AJ27 CVVT look fairly different:

AJ26 VVT


AJ27 CVVT

 

Len,

As stated, your model year would have an AJ27 motor, an external visual check is easy, the AJ26 solenoids face forwards and are on the face of the timing cover, the solenoids of the AJ27 face upwards and are on the top of the valve covers. (see pics below)






And per M. Stojanovic, the AJ26 and AJ27 units are visually different, the AJ27 having these cross-cut gear teeth (see pic below)




And finally, the bolt that retains the unit is different for the AJ26 and AJ27, the AJ27 bolt is hollow, and must be torqued to a lesser number during assembly.

Earlier AJ26 engines with solid VVT retaining bolts and should be torqued to 115-125Nm (85-92ftlbs)
Later AJ27 engines (like yours) have hollow CVVTs retaining bolts and should only be torqued to 85-90 Nm (62-66ftlb) A two stage torque sequence is recommended, initially 22-29 ftlbs, then a final 62-66 ftlbs.

.

 

Motorcarman: So, the guy I bought my `00 XJR from said since they don't have VVT, his mechanic told him the cam chain tensioners aren't really a problem on them. T or F? Thanks for all the good input!

 

totally false. The secondary are definitely a problem and with any mileage, your primaries will likely have signs of cracking, if not outright crumbling.