1998 V70 Timing belt, cylinder head work 330k miles!

Post by **Ozark Lee** » 03 Jul 2015, 07:24

Are you sure the single wire you describe really is black? Most of the ground wires that go to the block are bundled and bolt onto the block together. Since you describe it in the loom with the starter wires I suspect it is the solenoid wire, you don't want to ground that. There are three Red wires that all tie together on the starter on the large solenoid stud. The battery cable, the alternator cable, and the fan power wire. The fourth wire is the power to energize the solenoid when you go to position III on the key.

The knock sensors are touchy, they are picky about orientation and torque. Haynes is pretty good about describing their proper installation but I am at my cabin (On the flooded Lake of the Ozarks) and my Haynes is back in the city.

...Lee

5rivers · Post by **5rivers** » 03 Jul 2015, 07:42

Here are some pics that might help distinguish location of the black ground wire and knock senor clip:

: knock sensor location; Ground wire location.jpg (94.29 KiB) Viewed 1185 times

: knock sensor location; Ground wire location.jpg (94.29 KiB) Viewed 1185 times

: Knock sensor location?; Knock sensor location.jpg (133.8 KiB) Viewed 1185 times

: Knock sensor connection location; Knock sensor location1.jpg (139.2 KiB) Viewed 1185 times

I think the black ground wire is visible in one of the above pics. I have the two smaller clips attached - one to the alternator, another to the starter solenoid - and the red (positive) cable situated between the alternator and starter.

5rivers · Post by **5rivers** » 03 Jul 2015, 07:53

Sorry for the double pics; here is a wider view of general location of where the intake manifold stabilizer is bolted to the motor.

: Ground wire location1.jpg (96.35 KiB) Viewed 1185 times

Post by **erikv11** » 03 Jul 2015, 09:04

All grounds go to the block, I've never seen one on a bracket. Details below.

A couple days ago I pulled a blown engine from an NA S70, this weekend I am pulling the donor engine from an NA 850. The harnesses are different in that area.

Both harnesses have one short, black ground wire that goes to the block. The connection point is below and to the left of the oil pressure sender. The single ground wire splits off the harness midway between the little cluster that includes the alternator/AC/etc and the little cluster for the starter etc.

The knock sensors on the 98 each have 12 inches of wire on them, that connect together and then plug into one female connector that is very close to the main harness. Yours is appears to be like this from your pics.

On the 96 each knock sensor has a lead from the harness with a female plug, and that section of the harbess also has two grounds. Each is a multi-wire grounds, I think it was one black one pink, each connects to its own bolt on the block, to the right of the right-most knock sensor.

In both cases the knock sensor wiring snakes up between the starter and the block, you can get it through there without removing the starter.

5rivers · Post by **5rivers** » 03 Jul 2015, 09:20

Thanks Lee for your reply! The black ground wire is visible in the second pic above this message, the round metal connector is up against one of the power steering hoses. I don't have a Haynes manual to determine the clip/connector location for the knock sensors, but I do have to go the salvage yard today. Maybe I can figure out the connections on a '98 V/S 70 that hasn't had its motor torn apart!

ErikV11, thank you! There is a bolt in the location you refer to to the left of the oil pressure sender. On the harness of wires between the starter and alternator there is a clamp to hold up the group of wires, I suspect it attaches to the smaller of the two holes on the lower part of the intake manifold stabilizer that attaches to the motor - that might account for the bare (non-rusted) section around the backside of the smaller hole. Good luck with all your transfers!!

5rivers · Post by **5rivers** » 03 Jul 2015, 09:26

Just a note for clarification - the first 2 pics above are of the backside of the intake manifold stabilizer that attaches to the bottom of the intake manifold and the bottom part (pictured) that is bolted to the motor between the PCV oil breather and the starter. The pics are mis-labelled. The smaller of the two holes has had something attached to it - like maybe the clamp (I am guessing) that holds up the group of wires (harness) between the starter and alternator.

Post by **Ozark Lee** » 03 Jul 2015, 09:28

I have not encountered that wire before, it actually doesn't look stock.

The green/red wire that I was afraid you were going to ground is visible on the solenoid so I "assume" that the black wire gets grounded somewhere convenient.

...Lee

Post by **polskamafia mjl** » 03 Jul 2015, 12:14

I don't know if these pictures will help or not. They are from wheelsup's engine removal write up which can be found here: https://www.matthewsvolvosite.com/forums ... =1&t=28973

: 1.jpg (137.9 KiB) Viewed 1176 times

: 2.jpg (87.71 KiB) Viewed 1176 times

: 3.jpg (132.31 KiB) Viewed 1176 times

: 4.jpg (106.48 KiB) Viewed 1176 times

Post by **erikv11** » 03 Jul 2015, 12:26

That black wire is definitely a standard part of the stock harness, it connects where I mentioned.

Yes, the clamp on the harness is held up by the small (lower) bolt on intake manifold bracket.

5rivers · Post by **5rivers** » 04 Jul 2015, 06:28

Thank you polskamafia mjl, erikv11 and Lee!! My visit to the salvage yard confirmed the location of the connections (for the ground wire, wiring harness clamp, and knock sensor clip) as well. On my volvo, the knock sensor clip is attached to the black plastic covering (has an accordion look to it) to the large wiring harness just above the cross section of the front frame, which is different than pictured above (where the knock sensors are grounded to motor).

At the salvage yard, I was hoping to find a decent plug and wiring that connects to the thermostat temp sensor, but on every Volvo all of these plugs were snipped off. On mine the plastic coating on the wiring is splitting/separating just below the plug. I ended up covering each wire with some electrical tape, then taped both wires together up to what remained of the plastic tubes covering the wiring.

My next few tasks include installing the lower radiator hose, cleaning off old gasket material on the surface of the metal coolant hose attached to the rear (passenger side) of the motor. There are one or two more metal hose connections that need cleaning as well. Then the cylinder head gasket and cylinder head can be re-installed. I will keep you all posted on my progress, and of course, ask questions when needed. Thank you all for your replies and help

1998 V70 Timing belt, cylinder head work 330k miles!

Re: 1998 V70 Timing belt, cylinder head work 330k miles!