Heater Flap Fix

I noticed that when just driving around in the 944, regardless of whether my heat was on, my vents would blow hot air. Thankfully it turns out this is a common failure mode. The clip that holds the rod for the heat flap breaks causing the rod that actuates it to fail open (so you don't freeze in Germany during a failure). The actuator is located behind a plastic cover under the dash and you just have to replace the plastic clip and retainer, reattach the rod and you're good to go.

Broken heater flap rod clip

Clip and retainer replaced

Maintenance Update:

Mileage: 99,056

- New heater flap clip and retainer

Oil change for the 944

I realized it’s been a bit longer than usual since my last oil change on the 944. I had meant to do it last year while other work was being done but I must’ve forgotten so no better time than the present. 

Oil change time

Maintenance Update:

Mileage: 99,055
- 6 quarts Valvoline 20W-50 VR1
- Porsche/Mahle OC142 oil filter

New Seat Foam for the 944

The interior on the 944 is actually really clean and original. The only thing after 35 years is that the driver side seat bolster flattened over the years so I wanted to actually fix this to make things 100%. Unfortunately finding brand new OEM seat foam is difficult, if not near impossible, so I bought some new seat bottom foam from Design911 in the UK.

Seat out of car with new foam next to it

New foam

The only problem with the new foam is that it’s a bit generic for the standard seat so it’s not a direct replacement. It doesn’t have the appropriate cut outs for the power seat controls nor and doesn’t match all the contours needed to slot in to the seat frame.

Removing the seat cover and cushion from frame

New seat foam vs very old one

I spent several hours cutting and trimming the new foam to match the old foam then recovered and attached everything back to the seat frame. It was frankly way more work than I thought it’d be but not only does the bolster look better, the fresh foam makes the seat feel much better and supportive.

All the foam trimmings

Seat bottom frame

Everything put back together

Suspension refresh for the 944

I haven't been doing any motorsports events in the 944 because it developed a bit of a clunk when stopping at slow speed and the alignment wasn't what I wanted. I decided to get a fresh set of Konis and I'm glad I did since it turned out the old Koni front inserts started to have play in it. We reused the ground control coilovers that were already there and obviously the Racer's Edge camber plate that was also installed earlier this year. 

New front Konis installed

Rear Konis installed

I was also not happy with the uneven ride height so I had SJF reindex the torsion bars in the rear which unfortunately is easiest to do by dropping the entire rear and also had the front lowered a little bit. 

Reindexing rear torsion bars

The result was much more even ride height

LF - 25 1/2

RF - 25 1/2

LR - 25 5/8

RR - 25 1/2

The alignment was then properly done with the front camber maxed out. The rear is set 1 degree less, 0 toe and dialed in a little toe out in front to get better turn in.

We also noticed an oil leak from the plugs in the valve cover so new seals were installed. We also replaced the completely destroyed exhaust gasket. We then discovered the source of the clunk. The bracket that sits above the exhaust in the transmission tunnel wasn't fully tight. As soon as that was tightened, the clunk disappeared. 

Maintenance Update:

Mileage: 98,728

- New valve cover gasket and plug set

- New exhaust donut

- New Koni yellow all around

- New bolts and hardware for struts

Racer's Edge Camber Plates

One thing I wanted to fix on the 944 was the ride height. The rear sagged too much and the fronts were too high. I also didn't have enough camber. To fix this I bought a pair of Racer's Edge camber plates

I took the car to Lee at Hybrid Motorsports and had him install it along with reindexing the rear torsion bar (which I'll note appears to have already been upgraded to 27mm at some point) to raise the rear for a more even ride height.

Maintenance Update:

Mileage: 98,271

• Racer's Edge camber plates
• New OEM caster blocks
• Rear ride height raised
• Alignment

Fixing oil leaks and replacing fuel pump on the 944

I was continuing to have oil leaks from both the front and rear main seals on the 944 so I took it to Lee Autoworks to have this fixed once and for all. He found the crankshaft to having about 1.4mm of play which is well outside of tolerance which should be less than 0.4mm so we agreed to pull the engine out and have a closer look. 

Engine out inspection on the 944

The thrust bearing had excessive play and since the engine was opened up anyway, I had him check everything else out. There was a tiny bit of wear in the conn rod bearings and main bearings. Nothing to be super concerned about but I opted to have it all replaced along with all the seals since I don't want to have to do this all over again.

Fresh parts are here

I also took this opportunity to have the fuel pump, fuel filter, in tank strainer and hoses replaced so that I have peace of mind. I had no record of it ever being replaced and given the car is 33 years old I didn't want to have to second guess the fuel system so it seemed like a prudent thing to do. It did seem like it was replaced at some point so perhaps this was unnecessary but at least I know now exactly when it was done and it'll be happy for years to come. The crankshaft and camshaft position sensors also tend to go bad on these cars and given its age, I also had both replaced with new ones. 

He also go to the bottom of why the car kept stalling or having a no start condition. The connector for the mass airflow sensor was loose causing it to sporadically disconnect. He tightened up the connectors so it would have a firm electrical connection and now it starts like a champ every time. 

Engine back in and fully functional

People say these engines are some of the smoothest 4-cylinders ever made and while it was fairly smooth before now I really understand what they mean. At any RPM the engine is hyper-smooth with good power delivery. Such a joy to drive!

Maintenance Update:

Mileage: 97,356

- 6 quarts Valvoline 20W-50 VR1

- Mahle OC142 oil filter

- New OEM fuel filter

- New OEM fuel pump

- New OEM in-tank fuel strainer

- New OEM fuel hoses to fuel pump

- New OEM main bearings

- New OEM thrust bearings

- New OEM connecting rod bearings

- New OEM oil pickup tube

- New OEM crankshaft  position sensor

- New OEM camshaft position sensor

- Fresh antifreeze

- New engine seals

Fuel Pressure Gauge and Trans/Diff Fluid change

A few weeks ago I suddenly lost power on the 944 and ran into a no start condition. I swapped the DME relay and got it back working to limp it home and from my investigation it seems like it might just have been a bad ground caused by a bolt that had almost backed out all the way. Anyway, part of my concern at the time was whether or not I actually had fuel pressure but I had no way of telling. I got  Lindsey Racing fuel pressure gauge that fits right up to the rail so now I can see in real time what the fuel pressure is. This will help me detect any fuel flow or fuel regulator issues in the future.

Fuel pressure gauge installed

Fuel pressure gauge installed

While the car was on the lift I also decided to change the transaxle fluid since it's now been 500 or so miles since the new diff was installed and I figure that's a good enough break in period.

New gear oil

NOTE: I decided to remove the fuel pressure gauge shortly after since I didn't feel comfortable adding another potential failure point in case the gauge or fittings fail and starts to leak fuel into the engine bay. 

Maintenance Update:

Mileage: 97,305

- 2.7 quarts Motul 75W90 Gear Oil

New Oil Pressure Relief Valve

In January I changed the O-Ring and washer on the Oil Pressure Relieve Valve (OPRV) to fix a leak coming from it hoping that the valve itself or internal o-ring hadn't gone bad but it started to leak again so I decided to bite the bullet this time and just replace the whole unit altogether. Given how brittle the outer O-ring was, I suspect the inner one was just as bad and likely not holding the pressure as badly. 

Original OPRV (top) vs New Rennbay OPRV (bottom)

Rennbay makes a complete replacement that includes all new O-rings and washers at half the cost of the Porsche unit so I went with that ($225 vs $500). I've gone with Porsche or OEM sourced components or better up to now so why go with Rennbay here. Cost is one thing but from what I've seen so far the Rennbay kit is solid and replacing this bolt is a 5 minute affair so even if I had to change this again in the future I'd still be way ahead. After replacing the OPRV I took the car for a 50 mile drive and it was still dry so I think we're in good shape. I also noticed the dash oil pressure was looking more correct (a little over 4 at cruising). The old one would sometimes go to 5 and I think it may have been over pressurizing.

Maintenance Update:

Mileage: 96,993

- New Rennbay OPRV and washer

First autocross with the 944

Well you know this was going to happen. Finally took Stewie out for its first autocross. I wasn't really sure what to expect other than I was sure to have a blast again but also knowing I was going to be rusty since it's been 9 whole months since I last autocrossed.

NNJR SCCA Autocross 5-11-2024
 Photo by: Perry Aidelbaum

I had on 225/50R16 RE71RS all around and Koni shocks with ground control springs so I felt that it was the very least not going to suck. My first run was a terrible mess, less so because of the car but from me being rusty. I lost count of how many cones I must've smacked but it wasn't pretty. This car isn't exactly something that accelerates very quickly so it was almost like autocrossing in slow motion. I had a bit of time to think before each corner which felt a bit weird. I started with even pressures all around at 30psi cold but after feeling the car was a hair pushy I changed it to 29 front and 30 rear. That helped the balance quite a bit but allowing the front to work better.

The balance of the car was actually really neutral. I had no problems getting the car turning and the rear was so easy to manage. The diff was working perfectly and at the limit, it was a dream to control. Even when the rear wanted to kick out, I had plenty of time to correct and I didn't even have to lift. That said, the turn in speed wasn't there. I had to adjust my timing to turn in way earlier than I normally would but if I did, I could get on the throttle much sooner and the car just did it's thing. Honestly, other than the acceleration, I'd argue this car outhandles both my 911 and Cayman. It's just so well balanced.

After a few runs, I noticed some powersteering fluid coming out of the reservoir. I was carefully monitoring it and wiping it off before it got onto the ground between each run. When I got home I checked the fill level and it was definitely overfilled. I took some fluid out and now it's where it should be based on the dip stick so that problem should be gone next time. I also noticed the same around the brake fluid reservoir. That too was a hair over max so I took some fluid out so it'll be sorted next time.

I definitely enjoyed autocrossing this car. Sure it's not really going to be as fast as the other cars in its class (it is classed as STR as it stands right now) but I'm curious to see how I can improve this with more events under my belt. Each run I was already picking up more time so with only 6 runs and being a rusty driver, I left a ton of time on the table that I'm sure I could easy get back. I've got some alignment tweaks coming up that I think will make a big difference at the next outing. Overall the car worked really well and I really understand why these were so popular as track cars. Porsche really did a great job on the driving dynamics of these cars and it's a shame they are so under appreciated. 

Was too lazy to run a mic inside the car so excuse the wind noise

Drivetrain Refresh

When I got the timing belts and oil cooler sorted, we noted vibration in the torque tube at around 3500rpms. The 944 S2 uses a torque tube that has a split lengthwise that was designed to reduce harmonics and vibration. The problem is that over time this can spread over time causing the bearings inside to not sit properly. The vibration wasn't terrible but it was a sign of things to come and rather than wait for failure, I prefer to just fix it the right way the first time. I picked up a used late generation 944 from @944Barn on IG and had it delivered to Black Sea R&D in Georgia to have it fully refurbished and have their four of the steel shielded super bearings fitted. These bearings are made in the USA and built to better quality than the OEM ones from the 80s. 

One of the used later gen torque tubes from 944Barn

One of the used later gen torque tubes from 944Barn

Splines cleaned up

Steel shielded super bearings

 

Reassembled and powder coated

Since I was going to have the torque tube dropped anyway, it made sense to incorporate a number of normally labor intensive jobs as part of it to save on future labor. Looking at the previous owners' records the clutch was changed about a 13 years ago but the flywheel was only resurfaced not replaced. I ordered a brand new OEM clutch, flywheel, pressure plate and all associated hardware since it's almost a no brainer to do that now with it exposed as part of the torque tube replacement. With the clutch out it also made sense to replace the rear main seal. 

New Rear Main Seal

New clutch, flywheel and pressure plate in

Newly refurbished torque tube installed

The foam that goes under the shifter for sound absorption had already started to crumble over the years so I had that replaced too since you can only get to it with the torque tube removed. Glad I did that since the old foam had definitely seen better days.

New foam (top) vs old foam (bottom)

Last but not least, I got a Wavetrac LSD installed with new bearings into the transmission and also put in a fresh new OEM transmission mount. I've had good experience with the Wavetrac LSD in my 911 so I figured for the price and performance, this was going to be a nice little upgrade.

Wavetrac LSD

Wavetrac LSD

Transmission back together with WaveTrac LSD and
Motul SAE 75W90 gear oil

New OEM transmission mount

All these changes really brought the car to the level of "restoration" I wanted for this car. It's been well take care of and driven over the years and really needed some proper investment and effort to make it as good as it was when it was new. It feels transformed from the day I picked it up and I'm definitely very happy with the outcome.

Super big thanks to Marcello at Hybrid Motors for getting this turned our super quick and making sure everything was done right including addressing a few other small leaks we uncovered as part of this work.

Maintenance Update:

Mileage: 96,788

- New OEM Transmission Mount

- New OEM shifter sound absorber foam

- New OEM clutch

- New OEM Flywheel + new bolts

- New OEM Pressure plate + new bolts

- New OEM pilot bearing and release bearing

- New OEM clutch fork shaft

- New OEM needle bearings for clutch fork

- New OEM guide tube for release bearing

- New clutch bellhousing, torque tube, transmission bolts 

- New OEM rear main seal

- Remanufactured late gen torque tube with 4 stainless shielded super bearings by Black Sea R&D

- Wavetrac LSD (40.309.170WK)

- 3 quarts Motul 75W90 Gear Oil

Timing belts and fixing leaks

Looking back at the records, looks like the timing belts were last done 5 years ago. That's a "long" time for a 944 so that was on the top of the list of maintenance items I wanted to take care of. I also found no evidence of the motor mounts ever being replaced so I got a new set of OEM Porsche motor mounts. You want to stay OEM on the motor mounts because they are fluid filled and provide the right amount of damping. The cheaper aftermarket mounts die very quickly especially the one that sits closest to the header from the heat.

Service work done at Hybrid Motors

I dropped the car off with Marcelo at Hybrid Motors last week and they were able to turn the car around in less than a week. I had them source the timing belt, water pump and new rollers and while they were in there I also had them replace the motor mounts. Good thing I did as they were seized up there and worn pretty badly. They appear to be the originals from 1991 so they were long overdue. I also continue to see both an oil leak and power steering leak from the car before dropping it off so I had them take a look at it. The power steering leak was coming from the hose going out of the power steering reservoir. This is a common failure point so a new hose was installed.

New power steering reservoir hose

For the oil leak, it turns out the factory oil cooler was leaking. We could've tried just replacing some seals but instead I had them acquire and replace the entire oil cooler to make sure everything was just new and perfect. If the outer seals are going, you don't know what else could fail internally and cause coolant and oil to mix. 

New OEM oil cooler installed

Another common wear item is the cam chain guide. I had them replace that as well along with a new valve cover gasket to make sure I don't get any leaks after that work gets done. This is nice preventative maintenance as cam chain guides are made of some kind of hard plastic that can disintegrate over time. Not something I want in the engine. 

Old cam chain guide looking very tired but intact

The engine is humming along smoothly now with no leaks to concern myself about. I know I'm going a little overboard but I do treat every car I own as something I might own for a very long time so I try to make sure they are all brought up to proper maintenance rather than wait for things to fail. 

Old oil cooler

Old rollers and seals

Old motor mounts, timing belts, PS hose

Maintenance Update

Mileage: 96,660

- New OEM timing belts

- New OEM water pump

- New OEM timing belt rollers

- New OEM oil cooler

- New OEM valve cover gasket

- New OEM cam chain guide

- New OEM motor mounts

- New power steering reservoir hose