Surprising replacements

[the baron]

Just swapped out my rear boot struts  as I was getting bashed on the head but even when it used to stay up I don’t ever remember it actually springing up when you lift to the half way point, it literally just has a life of its own, I’d totally forgotten that they did this, well chuffed 

Anybody else replace something that has surprised you, the other that springs to mind is when I swapped out the suspension components and shocks and had the geo done, massive impact.

[½cwt]

Was impressed when I did my bonnet struts so I ordered the rear ones too, a bit less impressed but it behaves a bit more like a fresher car.

Most impressed was when earlier this year I changed the 6 year old N rated 205/50-17 Bridgestone S-02 tyres on the front which had started to show some cracks in the tread for 225/45-17 Goodyear Asymmetric 5s plus tracking adjustment.  Much better front end grip and gave confidence to push a bit harder when driving so got to enjoy the car a whole lot more.

[naim22]

MAF sensor

My mpg for mixed driving increased by about 5mpg. 

It somewhat made sense when I scrutinised the IAT data from the old Vs new MAF, but after doing this same job on a 2.7 previously I hadn't expected such a significant jump, just smoother running.

[½cwt]

13 hours ago, naim22 said:

MAF sensor

My mpg for mixed driving increased by about 5mpg. 

It somewhat made sense when I scrutinised the IAT data from the old Vs new MAF, but after doing this same job on a 2.7 previously I hadn't expected such a significant jump, just smoother running.

So @naim22 given your background and knowledge a useful occasional service part, particularly on a 19 year old car?  Are there any tell tales of reduced performance as opposed to completely failed that can be checked?

[the baron]

1 hour ago, ½cwt said:

So @naim22 given your background and knowledge a useful occasional service part, particularly on a 19 year old car?  Are there any tell tales of reduced performance as opposed to completely failed that can be checked?

Rev counter at idle can be rough, or erratic plus loss of mpg can be a sign, other than that, wait till it fails

[naim22]

In my case the symptoms were

On the 2.7, there was a slight hesitation usually directly after a gear change or during an accel at about 4K rpm. Fuel Economy was unaffected.

On the 3.2, I had uneven idle when warm to the point where the car sometimes felt it was going to stall (which I originally believed to be a dirty throttle body), poor mpg (although initially put this down to the larger engine) and the same hesitation seen on the 2.7

The first check was to unplug and see if driveability improved. On both my cars this did not illuminate any MIL lamp and the hesitation/uneven idle disappeared

I then wanted to know what was wrong so I compared the mass flow values with a known 2.7 987, and both vehicles showed mass flow readings in line with it. However the Intake Air Temperature values did not match (reading low) and were not really changing as the engines warmed up, whereas on the 987 2.7 they did (and also as the car idled and moved, due to heat soak/air flow) . The IAT reading was further out on the 3.2 which to me explained why it behaved like it did

In both cases the MAF removed was the 125.00 suffix. This was updated by Porsche to a 125.01 suffix at some point and this is what I put in both cars. I used a Bosch part but it had the Porsche part number marked on it.

I think I would be considering replacement only if I had any driveability issues that disappeared when the MAF was unplugged, or observed data from the DME showing erroneous input.

The job itself should be very easy but I did have to deal with heavily corroded/stuck screws on both cars and I replaced them also. This alongside the cost of the part would make me reluctant to change it unless I absolutely had to. 

[PaulQ]

I bought a spare Bosch maf years ago as apparently the 2.5 eats them, but I'm not sure mines ever been changed, so maybe not. 

 

[EXY]

2 hours ago, naim22 said:

In my case the symptoms were

On the 2.7, there was a slight hesitation usually directly after a gear change or during an accel at about 4K rpm. Fuel Economy was unaffected.

On the 3.2, I had uneven idle when warm to the point where the car sometimes felt it was going to stall (which I originally believed to be a dirty throttle body), poor mpg (although initially put this down to the larger engine) and the same hesitation seen on the 2.7

The first check was to unplug and see if driveability improved. On both my cars this did not illuminate any MIL lamp and the hesitation/uneven idle disappeared

I then wanted to know what was wrong so I compared the mass flow values with a known 2.7 987, and both vehicles showed mass flow readings in line with it. However the Intake Air Temperature values did not match (reading low) and were not really changing as the engines warmed up, whereas on the 987 2.7 they did (and also as the car idled and moved, due to heat soak/air flow) . The IAT reading was further out on the 3.2 which to me explained why it behaved like it did

In both cases the MAF removed was the 125.00 suffix. This was updated by Porsche to a 125.01 suffix at some point and this is what I put in both cars. I used a Bosch part but it had the Porsche part number marked on it.

I think I would be considering replacement only if I had any driveability issues that disappeared when the MAF was unplugged, or observed data from the DME showing erroneous input.

The job itself should be very easy but I did have to deal with heavily corroded/stuck screws on both cars and I replaced them also. This alongside the cost of the part would make me reluctant to change it unless I absolutely had to. 

Interesting point regarding corroded/stuck screws, worth doing next time you are in there I would think 🤔😁

[naim22]

Yes, definitely check them if in there, but as said I'd only replace the MAF if necessary. In my experience cleaning only of the MAF didn't resolve anything. And I would advise at least cleaning the old screws, or if damaged, replace. They are not expensive from OPC 

On one car I managed to get them out with a lot of patience, a Dremel to the head to cut a slot, a screwdriver and lots of penetrating oil

However on the other one, the screws sheared off clean flush with the flange. So I ended up modifying the air box by splitting the tube  between the box and holder, then obtaining a second air box without damaged threads to create that section from and joining with a silicone hose and clips. This effectively makes the MAF housing separately serviceable from the airbox without affecting the original positioning and housing diameter and the idea for this came from the later 987 design where the MAF and housing is serviceable without removing the airbox. 

It seems to me this area must get wet on 986s, and I wonder whether this is what eventually kills the MAF internally.

Once replaced/unplugged, don't forget to clear adaptive values. The bad IAT values seemed to throw the fuel trims out of whack. The new part resolved this.

[Southy]

Thanks,  just ordered two new boot struts 😃

[map]

This is in the spirit of @the baron‘s opening post but at a tangent....

As some of you know my 986S runs relatively specialist aftermarket coil overs and yet whenever I’m in a well sorted 986S running OEM springs and dampers I’m struck by just how right Porsche got it at the tail end of the last millennium 

Would I go to an OEM 986 chassis?

A properly early 2.5 yes in addition to my own slightly unhinged 986S - cake and eat it see...

[the baron]

3 hours ago, Southy said:

Thanks,  just ordered two new boot struts 😃

Frazer parts were £7.06 each + vat and delivery

[Senna]

On 12/29/2019 at 3:34 PM, Southy said:

Thanks,  just ordered two new boot struts 😃

Me too,

front and back