Variator Solenoid Diy Repair Guide

[alfizta 6]

This is a repair guide for "version 1" (not for "version 2") of the VARIATOR SOLENOID (a.k.a. variator actuator or variator control valve) on CF2 and CF3 (plastic cover) Twin Spark engines.

 

- If you get a P1653 fault code, you better check your VARIATOR SOLENOID before anything else.

- This part is located under the engine cover, between injectors 1 and 2, fixed with 2 Torx T30 bolts to the engine.

- Unplug it first, and check resistance between the 2 terminals. You should get about 12 Ohms reading. If you don't get any reading, then you can attempt the following repair.

- It's completely safe to drive with a faulty VARIATOR SOLENOID, but will take you considerable extra horse power.

- More than the Twin Spark technology, this is where most of the extra italian horses come from. This is the engine component that engages the Phase Variator.

 

TOOLS NEEDED:

 

- T30 and T40 torx keys;

- Philips screw driver;

- Multimeter with leads;

- Soldering iron;

- Electronic soldering mass;

- Optional: silicone sealant or equivalent and a 12V above 1A output power source.

 

PROCEDURE:

 

1. Unscrew the 4 T40 bolts and remove engine cover.

2. Unscrew the 2 T30 bolts that are fixing the VARIATOR SOLENOID to the engine.

3. Check reading on terminals (pic 1). On this one you are getting none.

4. Unscrew the 2 philips screws on top and remove de cap.

5. Check resistance again between the two metal pins (pic 2). You should get a reading now around 12 Ohms.

6. Put cap back on place.

7. With a bit of soldering mass and a soldering iron, melt the two metal bits on top of the cap (pics 3 and 4). This will provide electric contact with the pins underneath.

8. Check resistance again on terminals. You should get a reading now (pic 5).

9. You can test it with a power supply. Plug it to the SOLENOID VARIATOR terminals. A tiny metal piece should quickly pop out, meaning that it is working (pic 6). You can also do this check using your Alfa Romeo battery if you don't have a 12V power supply.

10. Put all back together.

11. Enjoy the ride!

 

- I also got the chance to add some sealant to the gasket around the Valve (pic 7), as these are known for leaking engine oil and getting your engine top all dirty. Added to the top of the gasket, as it is where it appears to crack and the oil gets spilled out. This glue is becoming handy in a lot of repairs...

- There's another version of the VARIATOR SOLENOID, I call it "version 2" (pic 8), but it's unrepairable.

- On CF1 engines (metal cover) this repair is more difficult. The engine cover does not allow you to take off all the bolts that fix the VARIATOR SOLENOID, or it is too bloody difficult to fit a proper tool to remove them. I also own a CF1 engined 146, and I can confirm this. Read on the web that is needed to take off the rocker cover to remove the part in question.

- Beware that both versions of the VARIATOR SOLENOID fit on every Twin Spark engine, but the metal plates supporting it are not interchangeable (pic 9 – V1, pic 10 – V2). Most of the parts sold on ebay are incomplete and some of them are missing this metal plate. So, if you buy it on ebay, make sure you are buying your version or it comes with the metal plate included.

 

 

CREDITS:

- Old Smaky's posts on P1653 fault code;

- Anonymous ebay seller, who sold me a faulty and incomplete but repairable "version 1" of the VARIATOR SOLENOID;

- My dear fiancée, who shot one of the photos.

 

[AFLA 4]

You have sealed it with UHU Max Repair which is a glue - and not a sealant per se? Why? I understand that this glue is flexible - but is it better for this task than "regular" RTV Silicone sealant?

 

And this is for the common variator solenoid seal leak?

 

I am asking because I suspect a leak there and want to verify I use the proper material.

[alfizta 6]

I just used what I had at home. Although it has a sealant function too.

It shouldn't be better than a silicone sealant, and should be more costly than the silicone too, but it works great and does not corrode the gasket, I can guarantee you. Tested on both my alfas.

 

Yes it is.

 

The leak is easy to spot. You'll see the surroundings of the solenoid gasket weted in oil. In an older leak all the area around the solenoid valve with be quite dirty with oil.

[imw1960 7]

Do you have to remove it or can you test and solder when its attached to the car

[alfizta 6]

yes, you can repair it without having it removed. that is the best option for the CF1 engines.

[Smaky 73]

 

And this is for the common variator solenoid seal leak?

 

I am asking because I suspect a leak there and want to verify I use the proper material.

 

A silicone sealant should be used, that glue will just melt when the engine gets up to temp and cause havoc.

[alfizta 6]

A silicone sealant should be used, that glue will just melt when the engine gets up to temp and cause havoc.

 

this glue states for temps up to 120 ºC. maybe won't last forever, but it's doing an excellent job on both my alfas

[alfizta 6]

Update. p1653 fault code returned intermittently. opted to completely remove the soldier caps on top of the solenoid, rubbed a bit to remove oxidized metal, and soldered all back together. no problems now. sorry, forgot to take pictures...

[Smaky 73]

You are able to check the resistance by just checking across the 2 soldered points on the cap, if that is OK and there is still a fault then check from plug pin to solder point for continuity.

[Smaky 73]

 

Edited August 31, 2015 by Smaky

[alfizta 6]

thanks, Smaky! will check that too next time.

[Smaky 73]

I say that because I have see n some where the cap was the problem.

[Paun 0]

Help p1654 alfa 147 2.0 ts

[Paun 0]

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