WillyC4S

Hello folks,

I've checked in the 944 Turbo forum for instructions on the removal of the oil filter housing for my '86 951 but I haven't found anything really detailed enough to explain the procedure as specified for the Turbo 944's. There's some instructions for the regular 944's, but our cars are different. In particular, I believe that the 951's heat shielding and how it mounts to the body and oil filter housing are not exactly the same. The picture in the Haynes manual looks nothing like what exists in my car.

A listing of the various bolts/nuts and their locations for the 951 heat shielding and filter housing would be a great start. I can't even see some of these fasteners when I'm trying to locate all the items needed to be removed to allow replacement of the housing.

1) My understanding is that there are 4 10mm (or 13mm?) bolts that hold the filter housing to the block; 2 of these bolts are located at the top and 2 at the bottom. And they are supposed to be removed from those respective access points (i.e. top bolts removed from the top and bottom ones from the bottom). The bolts are only accessible after the heat shielding is removed.

2) There are 2 10mm bolts that hold the heat shielding to the filter housing; the 1st one is located between the 1st and 2nd header pipes (almost directly underneath the 2nd header pipe) and the 2nd one is located at the front edge of heat shield on the lower section of the shield. The 1st bolt is accessed from the top with an extension and the 2nd bolt is done from the bottom(? ->looking for advice on how this one is accessed). It's pretty tight in there from the top to remove the 2nd bolt, although you can visually see the bolt.

3) There are another 2 10mm bolts that hold the shielding to the vehicle's body via a bracket. These bolts are viewable from underneath the vehicle looking upwards toward the heat shield. I suspect that removal of these bolts is done from underneath the car with an extension.

4) There's only one gasket that needs to be mounted to the filter housing and no O-rings need to be inserted between the filter housing and the block interface (unlike those pictures in the Haynes manual) since the new gasket covers the locations where the previous O-rings would seat. Is this correct?

5) There's only 1 (not 2) O-ring that goes around the filter housing's pipe extension (which is inserted into the engine block recess when the filter housing surface is mated up to the block surface). Is this correct?

6) I'm also planning to use a gasket sealer from 3Bond called 1211 on both sides of the gasket surface to provide a bullet-proof no-maintenance seal. Was told that this stuff is much better than the Yamabond 4 product. Anybody see any issues with this?

Is my understanding correct for the above and did I leave any bolts/fasteners out of the list?

I know that there's a bunch of other stuff that needs to be removed (passenger side sway bar bracket, ps pump, water pump if your doing the belts/pump anyways, oil lines, filter, ...) but I haven't mentioned those since that part should be the same regardless if it's the regular 944 or the 951 (only exception would be the oil lines coming off the housing).

I was wondering if someone who's done this procedure for the 951 be good enough to post this information for all us less fortunate ones.

Thanks,

*****

WillyC4S

Wow! Looks like very few people ever remove the oil filter housing to replace the seals.

Anyways here's an update regarding my removal of the 951 oil filter housing:

1) Removing the sway bar was really easy, especially if you've got an air ratchet to help speed up the process. Took no more than maybe 7-8 minutes to get the entire bar off and the passenger side support bracket (that mounts to the frame). First take off the A-arm nuts on top of the drop-link, then remove the nuts/bolts on the bushing bracket in the center of the bars; whole thing drops to the ground. Then take off the passenger-side bracket that mounts to the frame.

2) There are a total of 4 10mm bolts that secure the heat-shield down. The heat shield is composed of 2 pieces, a forward piece and a rear piece. The two sections of the heat-shield are secured together by 3 bolts that go on a bracket. This bracket is then secured to the oil filter housing by one 10 mm bolt towards the top left side of the housing, when viewed from underneath the vehicle. 2 out of the 3 bolts are ONLY accessible from underneath the vehicle. Removing these bolts requires the use of a 12" extension and a universal joint. The bracket bolt that mounts to the filter housing is also removed from underneath at the same time the other 2 bolts are removed. The 3rd heat-shield bolt is accessible from the top only. This bolt is almost directly underneath the #2 cylinder exhaust manifold. Again, use extension and universal joint to remove this bolt. I lost this bolt since it dropped out when I loosened it all the way.

The 4th heat-shield bolt mounts to the oil filter housing, towards the top right side of the housing. Use an extension and universal joint to remove this bolt from underneath the vehicle.

After all 4 heat-shield bolts and bracket bolt are removed, you can slide the forward heat-shield section forward towards the oil filter. You will need to remove the oil filter to get the heat shield out (see #4).

3) You should loosen the 17mm nut that holds the oil pressure relief valve in place. This bolt is almost directly 9 o'clock from the oil pressure sender. I didn't fully remove this until all 4 of the 13mm bolts securing the filter housing to the block was removed. Some oil will pour of this hole.

4) Oil filter will need to be removed, so prepare a oil pan to catch the mess. It helps to put some rags underneath the filter area to absorb some of the oil and prevent it from getting on all the lines, PS pump, ... etc.

5) Removing the oil pressure sending unit requires a wrench, but first you want to use a 7mm closed-end wrench to remove the nuts holding the 2 wires on the oil pressure sending unit. I put the nuts back on after removing the wires so I don't lose the small nuts. The sending unit base has flats on it for a wrench to fit around for removal and installation. I don't know the size since I used an adjustable crescent wrench. Once you break the torque on the sending unit, you can unscrew it by hand. Oil will definitely pour out of this hole so be prepared with the oil pan to catch this.

6) There are 4 13mm bolts holding the oil filter housing to the block; 2 on the top portion of the housing and 2 on the bottom portion of the housing. 3 of these are fully accessible from the bottom of the vehicle; the bottom 2 and the left top bolt are the ones you can remove from underneath the vehicle. The bottom right bolt will also have a bracket that holds the 2 wires which lead to the oil pressure sending unit. You'll need an extension and a universal joint to take these bolts off. When you loosen these bolts, coolant will spill out. I removed all the coolant from the radiator and the water pump (since I'm replacing the water pump as well), but there was still coolant in the area of the filter housing. It's not much, but be prepared to mop up the mess when it drizzles down as each bolt is removed. This would be more of a mess if I hadn't drained the water pump.

The 4th bolt is on top right portion of the housing, directly underneath the #1 cylinder exhaust manifold. You can see it from the top only and you can feel the bolt from the bottom. This was supposed to be the really tough bolt to remove, but it was a piece of cake (if you have an offset box wrench set, like I did). Took about 1 minute to fully remove the bolt and have the housing drop down! The offset box wrench just fit in and you have enough room for about a 45 degrees counter-clockwise turn, slow but totally comfortable and non-stressed. I fit this wrench in above the metal heater-return pipe that parallels the engine and goes to the firewall.

7) My old oil filter housing gasket is a metal gasket with rubber rings built into the gasket. These black rubber rings fit into the pre-cut grooves of the filter housing. They are no longer separate O-rings, but part of the one-piece metal gasket.

8) There is only 1 O-ring on the short oil pipe that's part of the filter housing. Mine was the original red O-ring, but I'm told the new O-ring is green. I haven't received the parts kit yet, so I'll just have to wait a bit.

9) You will need to have the large wrenches to remove the oil lines on the filter housing. I didn't remove these while the filter housing was still on the block. I waited until I could remove the housing to gain better access to the oil line nuts. Since I removed my water pump already, access to these nuts was very good from above. With the water pump in place, this would have been impossible. There are 2 nuts on the housing per oil line; one is larger than the other. I believe the larger is a 32mm and the smaller is 27mm. You need to hold one still and twist the other one counter-clockwise to loosen the nut from the adapter. Oil will pour out of the lines, so prepare to catch this spillage.

10) I removed the oil filter housing from above. Again, the water pump was removed, so this was possible (and extremely easy by the way). I haven't even tried removing it from the bottom where you have to twist and turn the unit to clear all the lines and other obstacles.

That's it so far. I haven't gotten the seal kit yet so the replacement story is forth-coming.

*****

Jeff Barnett

*****,
I replaced the oil housing gaskets when I did an engine rebuild (Head rebuilt, rings, rod bearings) with the engine in the car.

The new gaskets are all green. The old large gasket will need to be scraped out of the block (recessed if I remember) and not easy to do, plus you don't want any left over pieces getting sent though the oil system. I thoroughly vacuumed the area to make sure.

You should know that you are supposed to use an alignment tool to align the pressure relief hole with the engine block hole. I think this may have been more critical with the old pressure relief values (87s on have an all-in-one-piece valve). There are special tools, one for the old valve and one for the new one. According the tech bulletin in the back from the Porsche 944 parts and tech ref catalog, your 86 originally came with the old 3-piece value setup. There are 3 pages of text on this.

The net is this:

For 86 Turbo:
You MUST replace the old value parts with new retro fit valve (looks like the new one-piece values, but is special for the older blocks/housings).

Valve: 944 107 035 11
O ring: 944 107 935 11
Seal: N 043 815 3 (says to always replace this metal ring, so I did).

Alignment tool: 9215 (special for the replacement value types above).
You align the housing as you tighten the 4 bolts a little at a time, and move the housing to get easy push and pull with the tool.

I did not use the alignment tool, The key it to make sure the relief valve does not bind, so I tighten the housing while checking the value (by screwing it in/out) to make sure it moved easily). 10K miles since, no problems.

WillyC4S

Jeff,

Thanks for your reply. Lot's of good points.

The gasket was attached to the oil filter housing when the housing was separated from the block. My gasket came off fairly easily as a one-piece gasket from the housing. It seems there may have been some work done on the filter housing by the previous owner since my understanding is that certain sections of the housing were O-rings only w/o any gasket (which is unlike what I removed). There was no left-over material on the block to scrape off, but I'll scrub it anyways to get a clean contact.

Did you use any gasket maker or put the gasket on dry? I'm using 3Bond 1211. It's supposed to be an aircraft-grade sealant. I bought it from a Yamaha bike dealership after going in to look for Yamabond 4 or 5. The guy said they only use the 1211 stuff but will revert to the Yamabond 4 sealer if there isn't any 1211. At $17 for a tube of 3.5 oz, it had better be good! So far I've used it on the rear cam tower cover plate w/o the cork gasket (what a tight area to work on); don't know if any leaks will develop since I haven't put everything back together yet.

I did order the alignment tool for my model year of the oil pressure relief valve. It is more critical for the 3-piece relief valve since it's not a solid piece of metal like the newer valves (where you can test the fit for any binding like you had recommended). Most of the length of the 3 piece valve is actually the spring, so it's too compliant to check for binding and requires the tool.

On the subject of the new replacement valve, I did look into this but decided not to go this route since my valve was functioning correctly. I actually like the older part better since there are no wear items like O-rings to replace. I believe that Porsche recommends replacement with the new part if the old one is non-functional. At $250 for the part, it's not worth the change-over since it's highly unclear what additional benefits or gains are achieved with this upgrade (if you can even call it that). If the part were $20 or $30 I'd consider this a bit more, but that's not the case.

Jeff Barnett

I just used high temp RTV (I used it on the side with the groove, but not on the other).
BTW the new gasket is a new one piece with the new green kind of rubber, like the new o-rings, with a metal frame). The old type had 2 or 3 parts and were just rubber.

I know what you are talking about for the cam cover gasket, had that part off to pull the AC connection line from the firewall to replace the gaskets (did a 123a conversion 2 weeks ago).

Understand decision to stay with old valve.

As always, don’t forget to put oil on the o-rings.