If you are lucky enough to have a 991, model years 2012-2015, you have up to 8 of these little change over valves (COV) in your car. They are used to control things like sports exhaust and heater valve. If your heater does not blow warm air or does this intermittently, chances are that this valve has failed. They were poorly designed and subject to a recall no WC-43 but it seems that the improved ones fail as well. They are operated by vacuum and are part of a maze of vacuum pipes in your engine bay. The part number is 7PP906283C and it is inexpensive and not too tricky for a specialist to fit.

So if your 991 heater is not working, there is a prime suspect!

If you’re a water-cooled flat 6 Porsche owner, you will have heard of the dreaded IMS. Forums are full of horror stories and we have known people who have not bought one of these beautiful cars because if the fear of IMS failure.

It is true that the IMS bearing is a known weakness of these engines. However, failure is quite rare and, ironically, more likely to happen on cosseted low milers than hard driven high milers. The internet focuses on what is wrong with cars and creates an impression that all flat 6 water-cooled Porsches blow up. This is not the case, with only about 5% of affected engines thought to fail for this reason. However, as an owner, you will want to have a basic understanding of what the IMS issue is all about which is why we have written this blog.

What is an IMS bearing?

IMS stands for ‘Intermediate Shaft Bearing’, which is the supporting bearing of the intermediate shaft, on the flywheel end of the engine. The role of the intermediate shaft is to drive the camshafts indirectly off the crankshaft. By using an intermediate shaft, the speeds of the chains are reduced, which is better for the chain life. This basic design was used through the entire lifespan of air-cooled six-cylinder engines used through to 1998. You may be surprised to hear that the inclusion of an intermediate shaft, which drives the camshafts indirectly off the crankshaft, has long been a feature of the flat 6 engine used by Porsche as well as the water-cooled Turbo, GT2 and GT3 models as their engines are based on the same engine case and internals as the earlier air-cooled engines. This intermediate shaft features plain bearings that are pressure fed engine oil for lubrication and never fail.

Which models are affected?

All 986 Boxster models.
987 Cayman & Boxster models up to engine number 61504715
All 996 models (not including: GT and Turbo models)
997 3.6 with M96/05 up to engine number 6950745

What causes them to go wrong?

There was a fundamental change in philosophy with the water-cooled engines in that the bearing is a sealed bearing – in other words it is not lubricated by the engine oil circulating around the engine. All bearings wear eventually but the loads carried by the IMS and the lack of lubrication mean that they run hot and can overheat. This eventually cooks the metals in the bearing and causes too much friction, overloading the steel and fracturing it, leaving behind a jagged depression. Once this begins, wear accelerates and you have something of a ticking time bomb. However, as the seal starts to fail on the bearing, oil can get into the bearing and lubricate it. This is why many people believe that, once a car has done a high mileage, the chances of an IMS failure are, ironically, lower, resulting in it lasting the life of the engine.

What is the worst that can happen?

In the event of a complete failure, the cam timing can be lost, causing valve to piston contact which is terminal and your engine will require a full rebuild.

What gives the IMS bearing its fearsome reputation is that it can result in total engine failure with very little warning. Metallic debris in the oil filter whilst carrying out an oil change should make you suspicious. You may find that there’s an oil leak located at rear of engine, or you might have started to hear knocking and metallic sounds coming from the rear of the motor. Engine warning light and fault codes relating to cam timing is another clue. Clearly any of these warnings warrant further investigation and you should not drive the car at all until it has been investigated.

What can be done to solve the problem?

If you are buying a car and have a choice of one with an IMS upgrade then it is worth paying more for that car. If you already own the car, then options are limited. Don’t treat the car with kid gloves – low mileage and lack of hard use make the risk higher, ironically.

Many people believe that Porsche should have made the IMS bearing a service item. To replace the bearing, you have to remove the gearbox, clutch and flywheel, which is what makes it such a big job. Our advice is to routinely upgrade the bearing if you ever have to remove the gearbox. With clutches often only lasting c 50k miles, a logical thing to do is to do the IMS bearing if you have a new clutch fitted.

Porsche do not sell a bearing on its own – they just sell the whole shaft, which is only fitted as part of an engine rebuild. Fortunately, the after-market is well served and there are upgraded bearings which can be fitted without stripping down the engine. The one that we use is the EPS Eternal Fix bearing kit. This has a patented roller bearing design which can handle loads 12 times higher than the standard ball bearing unit.

We have done a number of IMS bearing replacements. We prefer to take the car back to our workshop than do it via our mobile workshop. You should not live in fear of Porsche IMS bearing failure and can drive your car as it was designed to be driven. Stop driving and seek advice if you do see any of the warning signs but do not be paranoid. Then plan on a routine upgrade if your gearbox has to come out and you will not need to worry again.

If your Porsche Cayenne shows airbag fault code 1217 1218 and the airbag warning light is on, Googling the code will be confusing because you will get lots of responses for Audis. Fear not, VAG used the same part in Cayennes and it is a simple fix. It is likely to be corroded plugs.

So if your airbag waning light is on and you get Porsche airbag fault code 1217 1218, fear not. Just get in touch and we will get you going without a huge bill.

The biggest challenge for a mobile Porsche specialist is how to replicate the lift that your specialist or OPC has. We turned to Formula 1 for inspiration. Our high tech lifts are hydraulic and work off our own 12V supply. They are a thing of beauty to watch as you can see here and give us more than enough room to do all of those jobs from underneath, including engine removal. They are also very secure and safe, important both for your car and our technicians. As you can see from the photos, the lifts can be used in your drive, parking space at work or anywhere else flat. Your car does not need to be moved!

While the 924 never really shook off its VW origins, the Porsche 944 was an altogether different beast. An all new slant 4 engine was essentially half of a 928 engine, giving it genuine Porsche pedigree, reflected in the power and durability of the unit. The rest of the car was heavily evolved from the 924 with timeless looks, a great power to weight ratio, even in 2.5 guise, and it is one of the best handling Porsches ever made.

If, like us, you have always fancied owning a 944, hopefully this Porsche 944 Specialist Guide will help you find a good one.

Overall

As with most exotic cars, buying a good one to start with is critical. Even though values are rising, a nut and bolt restoration is still not a viable financial proposition unless you have the skills to do the work yourself.

The most important thing is the condition of the bodywork. Walk away from any signs of accident damage in the form or poor panel gaps. Equally be very wary of rust. If in doubt walk away again – there are enough good ones out there to avoid the expense of extensive rebuilds.

Mechanically you can take a few more risks. These  are very strong cars and the engines will do huge mileages if properly maintained, as will gearboxes. Given their age, most cars will have one or two electrical issues but these should not be walk away issues.

We would always advise against cars that are modified in any way – originality is key to long term value as well as reliability.

Mobile Porsche Specialist is based in Berkshire and we have just travelled all the way to Cheshire to retrieve our new 1987 Porsche 944 2.5. Below are some of the things that we looked out for – hopefully useful to you.

Engine and Gearbox

• The engine should have been serviced every year or 12000 miles. If there is poor service history, while it might not be terminal for the engine, it says all you need to know about how well the car has been maintained – walk away! Properly serviced with an annual oil change these engines go on and on – there are lots of cars running beautifully with over 250k miles on the clock. However look for smoke on higher mileage cars. It might just be valve gear but bore wear / piston rings would be expensive.
• Timing belts must be replaced every 4 years or 48000 miles and we recommend replacing the water pump at the same time. If there is not clear evidence of the timing belt having been replaced in the last 4 years, then do it urgently. Failure is terminal.
• The more complex 16 valve engines are slightly more fragile than the 8 valve due to the small toothed belt which drives the exhaust cam – this needs to be change every 4 years.
• White sludge in the coolant header tank could indicate a cylinder head gasket failure
• Oil leaks around the oil pressure sender, oil cooler, balance shafts and camshaft are not walk away issues but will mount up in labour.
• Vibration at idle is most likely worn engine mounts, rather than something more terminal.
• The ignition system is weak and these cars are notorious for not starting and cutting out. Not starting and / or cutting out when warm due to no spark is likely to be the DME relay, a well-known 944 weakness – it is almost worth carrying a spare. Coils are unlikely to go but just routinely replace the distributor cap and rotor arm. The crankshaft speed and reference sensors are the other main culprit to non starting and you can check their resistance to see if they are faulty. If still no spark, check the DME ECU and the loom between it and the sensors. You will get there in the end.
• Steering pumps and racks can leak, as can power steering pumps, although the latter may just be old hose clips.
• Gearboxes are tough and long lasting whether manual or automatic. Any whines from the rear are likely to be differential bearings.
• You may find leaks from the two output shaft seals. Regardless, we would always do a transmission oil change, unless there really was evidence of a recent one.
• Check the clutch as you would on any car. There should be no slip or judder. If there is, it is not terminal but you will face a big bill compared to less exotic machinery.
• Starter motors are all slow on 944s.

Bodywork

• Assuming no accident damage, your biggest worry is rust. These cars are 30 years old and many are still used as daily drivers.
• Rust areas are fairly obvious:
  • Check the sills, especially if there is under seal painted on them
  • Muck collects in the bottom of the front wings, causing corrosion
  • There may be blisters between the front wing and bumper and the rear panel and bumper. If there is a blister there will be a hole.
  • Check around the windscreen for blisters.
  • Have a good look underneath, in particular where the rear beam mounts to the body, which would be an expensive MOT failure if corroded.
• Wet carpets may indicate a leaking sunroof due to old rubber or a broken mechanism. Check that all is working properly.
• As with all Porsches, welcome to a life of stone chips! A few will indicate an honest car but if there are lots you will need a front-end paint job. It may then be worth wrapping the front in protective film.

Suspension

• Despite the name you are just looking for the usual suspects. Bangs and clonks mean work but do not mean you have a bad car. Ball joints are the usual suspect and the rear anti-roll bar bushes can wear.
• If your 944 handling is not razor sharp, go looking for some play – not big money but worth getting suspension perfect for your enjoyment.
• If the car has not been used recently you may find that one or more of the brake callipers stick and the brakes bind, requiring a straightforward strip and rebuild.

Electrics

• With the Porsche 944 now around 30 years old it is reasonable to expect some electrical problems to check what is and is not working. No need to walk away if something is not working but you need to budget for some work.
• Known weak spots are slow windows, stuck mirror adjusters, rear wash wipes, headlamps not raising, and fan problems so make sure you check all of these.

Interior

• Typically 70s/80s Porsche, the 944 interior is functional rather than luxurious. The condition of the interior tells you a lot about how the car has been treated by previous owners. Be wary of one that is heavily worn.
• Most materials are hard wearing but seat fabrics can wear with re-trimming being a costly route.
• 30 year old rubber will likely be perished and the boot seals might be leaking, resulting in fumes and a wet boot.
• The luggage blinds often do not retract fully.
• Bonnet and boot struts are not particularly long lasting.

 

Mobile Porsche Specialist is a mobile specialist. We bring our state of the art mobile workshop to you. We have Porsche specific diagnostics and a ramp for all of those jobs done from underneath. If you would like help with your Porsche 944 please contact us for a no obligation chat.

Welcome to our new website! We hope you find it helpful and welcome any suggestions for information that we could provide you with.

We start trading in Buckinghamshire, Berkshire and West London on October 1st and will be open for bookings from September 1.

Our aim is to help our customers get more enjoyment out of their Porsches by minimising running costs and improving reliability and originality. We want to share our experience of and enthusiasm for Porsches with you and, by coming to you, involve you in the process.

We are keen to take on board the thoughts of our customers – if you have any suggestions for the service that we can offer please contact us with your ideas.

Good company in a journey makes the way seem shorter. — Izaak Walton

When we set up Mobile Porsche Specialist, we wanted to make sure that from day 1 it was based around the needs of our customers. We spoke to over 100 Porsche owners and listened intently to what they said. Here are some examples of things that we have heard and taken on board:

“Good availability of parts. Excellent knowledge”

“Offer oe parts and non-oe parts, have nice paperwork so that the receipts look good”

“Don’t charge ridiculous sums and know where to get good-value parts.”

“Be friendly, not patronising as I’ve found with some (I’m female). Also don’t bump up ‘necessary works’ to push up the bill. Excellent idea tho’. Good luck”

“No flannel :)”

“Have all the tools”

“The main issues I would have are :- Could I see reviews and recconendations from other porsche owners. How much porsche experience and knowledge do they have. Finally are they good to deal with because we would all rather use someone we liked”

“Join a forum”

“Be able to work on older model’s and know where to get part’s from, although I can aslo help with getting part’s.”

“I have several older porches 944s and 911sc so experienced and knowledge with older cars would be essential also cost effective.”

“Don’t assume we’re all rich and try to rip us off because we own a Porsche.”

“Quick and great services without any bullshit or rip off”

“Honesty, sensible pricing and having the correct tools and diagnostic equipment to do the job! Also would like to know the ability to change water pipes, coil packs on a 997 turbo, air filter on a 991 and bleed up the coolant system….these are not jobs that can be done on the floor!”

“Demonstrate car can be fully checked without a ramp”

“Friendly”

“Fair price. It my be a Porsche and my pride and joy but don’t take the piss”

“Know what your on about!”

“Understand that although they are specialist cars real people own them, not just football waged stars”

“Reputation is everything.”

“Ability to discuss needs of the car with the owner.”

“I would need someone to do the jobs I don’t have the facilities, tools or knowledge to do.”

“Good access to older parts”

“Be professional, be prepared to explain items that need work. Don’t be evasive if asked a question.

“Honest, reliable, does the work needed and not exploiting more jobs that aren’t needed. Reasonable prices, friendly, approachable. Knowledgeable within specifics and loves your car as much as you do. Someone who has a genuine passion for Porsche Happy to provide advice as needed.”

“Know the local established competition, be clear about what you’re offrring, be very customer focussed”

“Show your credentials and experience in order to get the work”

“Get out and meet them”

“Be careful what you take on. Some jobs just aren’t mobile suited. Clutch,flywheel and IMS for example.”

“Don’t try and rip people off with things that don’t need doing!”

“Be trustworthy and reliable and knowledgeable like my current one is.”

“Use genuine parts and keep everything original”

“Attention to Detail. Clean. Diligence. Honesty.”

“Be on time”

“Honesty, enthusiasm, flexible times and in-depth knowledge.”

“Make sure you have all relevant diagnostic tools for older cars “

“Demonstrated track record”

“Be as transparent and up front about pricing from the start. Why do repairs bills always spiral out of control? As a Porsche owner, I’m always treated like I have incredibly deep pockets and am happy to throw away money on repairs that don’t really need doing. I’m sure you’ll get lots of work as a mobile technical but I’d also recommend you act a mobile second opinion that can evaluate the proposed work of garages prior to it being undertaken. If they’re confident in their prognosis, they should have no problem with you turning up. In sum, be truly independent and make sure you prioritise good reliable communication with your customers over everything across all mediums (WhatsApp, email, text, telephone).:”

If you would like to share your needs relating to Porsche maintenance, please contact us here.