teeerex

Hi - done this myself and agree a complete PITA to get it back as well. Stating the obvious maybe, but you do realise that the tank does not slide in from the front - it slides in from underneath (matching the tank slot with the holder slot) and then once 'up' push back away from the engine and it will slot into place (with a good wiggle/shove I should add...) Yep lube will help, I just used plain old water so it wouldn't make a mess. I also recommend getting on the rear coolant pipe before you push the tank home - you get more space to get that clamp on that way - the small one and bottom one can be done when the tank is fully home no problem. Also if it's a C4/GT3, remember to fix the Fuel filter in place as well before you finalise the position... Remember to seat those pipes properly and endure the clamps are just after the 'bump' in the plastic. Good luck - good sense of achievement though once you've done it ...

My logic tells me they are for any accessory bottons in the console itself - just under the cubby hole. Obviously you no longer have any of this now - so just tuck them away, cable tie them to something if you can to stop any potential rattles later on ... Richard.

Are you saying that the problem started since you had the new clutch fitted ? If so, and Porsche can without doubt say that this caused the engine failure, then it's really irrelevant how much Porsche are asking for because the mechanic that screwed up will be paying for it surely ? Sounds a bit iffy though because if Porsche are paying 1/2, then they are either being very genereous (unlikely!) or they are partly to blame in some way? Surely if it was a loose bolt, they would be able to find it, or shreds of it anyway ?

..just to complete the topic - these pic's may be useful to someone in the future - use to supplement Loren's DIY ... 1. Make sure the transmission is hot / engine is hot - a good freeway thrash should do it .. 2. Jack up the rear AND the front of the car - it is important the car is LEVEL otherwise the oil level will, one not all flow out and two, be the incorrect amount when you refill it. 3. Start with the FILLING plug - if you can't shift this, then at least you can take the car to the OPC and let them do it ! 4. On MY99 C4 the filler/plug is a 11mm Allen type plug so I used an 11mm 1/2" Drive Socket + sufficient leverage (in my car a 2ft breaker bar ..) 5. Remember to have a tray to catch the oil ... 6. It will gush out once the plug is removed so don't get scalded ... 7. Plugs :- 8. Filler hole :- 9. Drain hole :- 10. Leave it to drain for 15-20 minutes .. 11. Refit the drain plug - to 30Nm :- 12. I used a 'bug spray' system to pump in the new oil. To do this effectively the oil really needs to be warmed up or the pump rate is very slow. I simply filled the pressure bottle up with 3L of oil and left it in the airing cupboard for a few hours.. 13. Using maximum pressure (about 3bar) I simply put an extra piece of tubing on the end of the spray arm and pressed the trigger - not a single drop split... 14. When you get near to full, slow down a bit and watch for when it comes back out the filling hole. Tip here is to use the gauge on the side of the pressure bottle to give you some indication ... 15. Put back the filler plug - again to 30Nm :- 16. Clean up the overflowing oil and plugs etc 17. You're done ! I've omitted the front diff (C4's only..) as once I find a reasonable way to get off the filler bolt, I'll update this post ... Cheers, Richard.

What kiind of pump are you using for this? Where did you get it? --- Tom Hi - I'm just using a 'bug spray' pressure bottle, removing the spray head and fitted a short length of polytube. bottle and then filling it with Transmission oil instead ! I've warmed the oil first to make it as liquid as possible and it pumps it fine. I've even got fingertip control via the switch on the sprayer ! I also plan to use this for a pressure brake fluid bleeder once it's all cleaned up ! I'll post again once I've suceeded in this .. (similiar to the 'Motive' bleeder - but at about 1/5 of the cost ...) Success in getting the caps out btw - use a 1/2" Drive 10mm allen socket and a 2 ft breaker bar and it snapped open after a significant amount of pressure - that was no low torque setting ! 3/8" socket would have snapped I think. Only partial success though as the front diff is 17mm Hex Bolts - I can get to the drain one easily, but the filler one is a pig - I've rounded the head as I can't get any pressume onto the socket to keep it in place - even with a extension bar. I may have to remove the near side front wheel and use a very long extension bar ...

Loren - ok thanks for the reply. Perhaps the new models use a large Allen size so they can undo them without snapping the 10mm allen socket like I probably will tomorrow ! How about a hot transmission and I freeze the bolt (with freezer spray) and then try the pen oil for a few more hours ... it may crack the chemical bold enough for pen oil to get in there ... Tried to tighten the bolts too - as I know this sometimes breaks the bond enough to then undo it again... Why couldn't they just use a normal hex headed bolt ?! Richard.

Hi - I am just doing some prep work for changing the transmission oil on my MY99 C4, I have the Oil, I have a pressure pump to pump it in but I can't undo either of the filler/drain bolts on the rear transmission ... btw Loren - on my car they are 10mm Allen for both, not 17mm (that is very large - are you sure that's correct, that's bigger than the bolt itself (!). Anyway, I've sprayed with penetrating oil and will leave overnight to see if that helps. Transmission is 'warm' - plan was to loosen the bolts and then go out for a run to get it nice and hot before draining. Car has done 55K so assume they haven't been cracked opened in a while ... Has anyone got any ideas on how to loosen them - 3/8" socket bar is physically bending with the pressure I'm putting on it - don't really want to snap the allen in the bolt ... <_< Perhaps try it when it's cold, or perhaps very hot ? PS - Haven't even looked at the front diff yet ... Thanks! Richard - UK.

We have the same issues in the UK with regards to getting hold of any of these 'recommended' oils. I've found out that Silkolene make an alternative (race derived so may be superior and is fully synthetic) :- Silkolene Silktran SYN 5 API GL4/5 75W/90 Which matches the Porsche specification perfectly - and is definately a Transaxle oil. I got mine from a UK distributor for £8.99 per 1L vs Porsche's £15.00 per 1L so cheaper too ! Also fantastic service from them with next day delivery. PM me if you want details ... Cheers, Richard.

Hi - I've been playing with the air box myself and just read your post. Surely it's the Schnell pipe replacement that is now making your extra intake sound - the extra resenator box sitting inside the main air box is sealed from the main unit and is essentially surpless to requirements once you've installed the Schell. I guess you can remove it (as you have suggested) but other then increasing post filtered air volume in the air box, I'm not sure what you have gained ? Also, I've read that the pre MAF plastic lattice that you removed is used to 'straighten' the air going over the MAF ? Just some thoughts .. Richard.

:eek: Don't have the engine running or you'll suck the cloth into the engine ! Use both the spray and a cloth ...

Hi Glenn or Richard, is there a DIY or is it just pretty much self explanatory? Anyone took pics? I started to notice that my idle is a little rough lately. How much time would you estimate for the job? Thorsten Hi - would say 10-15 minutes at the most. You just need to remove the large black rubber snorkle going to the throttle body - loosen all 3 jubilee clips (use 7mm female hex socket if I recall) holding the snorkle (2 on the air box, 1 on the throttle) and pull it off. Depending on the year of car, you may have some other connections. Push the butterfly valve open SLOWLY (it's geared on egas models) and start cleaning. Use a lint free cloth so you don't get fluff in the chamber. When you've cleaned it all up (all round the inside of the metal body and valve too) then put it all back. You may find it easier to loosen the air box to get the snorkle back on (13mm bolt next to the boot lock if I recall) - sorry this is all from memory! Most important bit is to get the jubilee clips in the centre of the rubber channels and make sure they are like this all the way around - not just the bit you can see ! Suggest putting the air box end on first and then the throttle body. Regards, Richard.

Hi, Just passing on some info that's been covered before in this site but for me it's made a huge difference to drive quality. Whilst putting back my air box I decided to have a look in the throttle body so I removed the funnel and slowly lifted the butterfly valve - it was black and I mean black and as expected was covered in petrol. I wiped / scrubbed all that I could get to with a cotton lint free cloth , and all the carbon came off very easily - I had no need for the carb cleaner but I expect this would have made it easier. I got right inside the body and cleaned the butterfly valve as well. Anyway - once splotless, I put everything back, seated properly and air tight. I noticed an immediate improvement on idle at startup. Drove down the drive and again noticed a significant improvement in smoothness and pickup. Ok that was with a cold engine. Once at normal temp, the whole car was so much smoother and low rev torque/pick up was soooo much better ... Er... all this from cleaning the throttle body ? My car has done 54K miles and it looked like it had never been done - but if this is the improvement (dramatic in my opinion) then why is this not included on say a major service (the car had one at 48K miles). So - in short, next time you replace your air filter, do the throttle body at the same time... Cheers, Richard.

... so it costs £300+ for a plastic box and a cone filter - and it still sucks in the hot air because it not enclosed ... :-( I originally thought the bootlid 'sealed' the Evo box when shut, but looking at the picture in detail - this doesn't seem to be the case... .. Hmmmm .. think I'll stick to a DIY case which I know feeds only cold air ...

Hi - to be honest, I don't believe that is the primary function of these holes. The water must exit at the 'lowest' point which is hole in the bottom of the air box - made obvious by the water marks leading to it. This hole also deposits any water in the gap behind the engine by the belts and onto the floor - no I believe those holes are 100% for air intake or balance only. Taking another look at the holes - getting cool air to them is going to be more of a problem than I originally thought due to the a/c lines - there isn't much room in there... I'm taking the tape off for the moment, but may cut a second hole into the sub frame of the Aero kit just to feed it cold air by convection .... Thanks for your thoughts... Richard.

OK - tks for replying. Just to satisfy my curiosity, I blocked the holes with gaffer tape and put the air box back together again. I noticed immediately that there was substantially more 'suck' now on idle from the snorkle to the lid - infact I nearly caused the engine to stall as my hand was sucked hard onto the tube. I guess this is 'correct' as the air now had no other point of entry. Performance wise, the car did seem a bit more hesitant, little less induction noise - but that could be me - nothing scientific ... :-) So lets say that 30% of the air comes from these holes as opposed to the main duct - I guess getting a cool air supply to the 'other' end of the air box may give a small % performance increase ... Hmmm something to consider as I only have a layer of thin fiberglass between another snorkle and the 'fake' vent in the right hand side of my Aero spoiler ... Watch this space ... Richard.

Hi, Just wondering why the stock air box has lots of factory holes in the right bottom of the air box ? These are clearly in the engine compartment sucking up nice hot air ? (ie not good). They clearly pick up their fair share of the air because the immediate filter above them is dirtier than the rest after only 1-2000 miles .. Mind you, I guess any air from the engine compartment / lower to the ground will be dirtier than on engine lid... Are porsche sacrificing a tiny bit of performance for some added induction noise - or is the funnel to the engine lid too restrictive at full throttle ? I'm tempted to block them up to see what difference it makes ... anybody else done this or have any ideas ? ? Richard.

Ok Thanks - but I'm a tad confused now. Are you saying this sensor monitors both the air temperature of the engine compartment AND the coolant temperature ? (it does have 4 wires I have noticed). If so, how can it monitor the air when it's almost at the bottom of the engine - surely the sensor should be at the top near the lid ? (not that I'm doubting you - just doesn't make much sense..) Also, I assume if I replace the whole sensor - I'll need to catch the coolant as I assume I'll make a hole in the block when removed ! Thanks - almost there I think ... Richard. Further update - I called Porsche East London to find out the cost of the engine coolent thermostat (£11.27 btw) and they advised that there is a 2nd sensor as I suspected called the 'Ambient Temperature Sensor'. (Great service from Porsche East London parts department - thumbs up) It is located in the plastic inlet manifold on the right hand side of the engine. I've been told that it sometimes pops out of it's mounting and causes this problem. Reseating it should solve the problem. This sensor is only £14.71 but they said they haven't ordered one for 3 years so sounds very reliable. I'm at work at the moment so will check this tonight and report back ... Hopefully this is the problem ... Cheers, Richard. I made a mistake. The sensor in the lower picture IS NOT the engine compartment sensor. I didn't look at the picture close enough yesteday to see the coolant hose. That is the temperature sending unit for the coolant. The sensor you are looking for is located on bank 2 (right side of engine) on top, between the middle and back intake shown in the first picture above. It is a 2 wire sensor and your can remove it by sliding ut out towards the right fender. Sorry for the mixup. And YES, it can fall off and sit on top of the manifold, raising the temperature it reads. Resolved ! - Thanks to all - It was indeed the sensor that had fallen off and was resting on the engine block itself. It fits in the first gap between the first two inlet manifolds on the right hand side of the engine - took some pictures to assist if anybody else has the same problem :- 1. I traced the wires going into the inlet manifolds and pulled out ... 2. I tried to fit it into the holder but found it too tight and didn't want to foce it. Therefore, I took out the sender from the grommit, used some WD40 on the grommit and slid that in first... 3. Then it pushed the sender unit into the grommit from underneath until it clicked into place. 4. A picture of the sender poking it's nose into the air taking the ambient air temperature - as it should be ! Cheers, Richard.

Ok Thanks - but I'm a tad confused now. Are you saying this sensor monitors both the air temperature of the engine compartment AND the coolant temperature ? (it does have 4 wires I have noticed). If so, how can it monitor the air when it's almost at the bottom of the engine - surely the sensor should be at the top near the lid ? (not that I'm doubting you - just doesn't make much sense..) Also, I assume if I replace the whole sensor - I'll need to catch the coolant as I assume I'll make a hole in the block when removed ! Thanks - almost there I think ... Richard. Further update - I called Porsche East London to find out the cost of the engine coolent thermostat (£11.27 btw) and they advised that there is a 2nd sensor as I suspected called the 'Ambient Temperature Sensor'. (Great service from Porsche East London parts department - thumbs up) It is located in the plastic inlet manifold on the right hand side of the engine. I've been told that it sometimes pops out of it's mounting and causes this problem. Reseating it should solve the problem. This sensor is only £14.71 but they said they haven't ordered one for 3 years so sounds very reliable. I'm at work at the moment so will check this tonight and report back ... Hopefully this is the problem ... Cheers, Richard.

Ok Thanks - but I'm a tad confused now. Are you saying this sensor monitors both the air temperature of the engine compartment AND the coolant temperature ? (it does have 4 wires I have noticed). If so, how can it monitor the air when it's almost at the bottom of the engine - surely the sensor should be at the top near the lid ? (not that I'm doubting you - just doesn't make much sense..) Also, I assume if I replace the whole sensor - I'll need to catch the coolant as I assume I'll make a hole in the block when removed ! Thanks - almost there I think ... Richard.

Update : I've checked the relay's - They don't seem to be numbered (?) so checked all the relays matching that part number (4) - VW Part btw.. - All had a coil resistance of 68 Ohms, all N/O contacts were open ie no stuck contacts, and all operated normally closing the contacts when +12v applied to the coils. I guess it's not those then... Sender unit on the coolant tank was replaced when I did the tank - double checked the connection there and looks good. Temperature sender in the engine bay - er.. where is it ! I think I've spotted the main coolant sender (pic attached) and another 'sender' type component with two wires coming from it (both attached) but can't see anything obvious that monitors the 'air' temperature in the engine compartment ? Thanks for your help so far ...

Excellent - thanks 1999Porsche911 and Loren - I'll post the outcome ... :-)

Hi, I know this topic has been done to death and I've searched for as much info as I can find on this excellent site. However, I would like to know why my engine compartment fan turns on without fail and refuses to turn off, when my coolant temperature reaches what I believe to be 'normal' - ie needle dead centre. Car : 996 - MY1999 UK Spec -GT3 Aero with Row030. I have personally replaced the coolant tank with the latest model and latest cap - after the previous one split. I used Porsche antifreeze with a 50:50 mix of distilled water to fill the system afterwards. Coolant levels are static, Purged/Burped for a couple of weeks now, No water in the oil, Compartment fan draws air 'in' as normal. Oil/Filter recently changed after 2nd track day. Front Rads have been jet washed clean with the front bumper / AC Condensors removed - both front fans work fine - they do not cut in until I have been sitting in traffic for 10-15 minutes (ie normal) If I turn the ignition off and restart the engine then fan comes back on after a few minutes and again, fails to go off - this can happen with 'normal driving', motorway normal driving or heavy track day driving. Throughout all of these scenerio's the temperature remains at a perfect top dead centre, or slighly over in traffic. (which I believe is 'normal') I think I've covered all the 'try this' suggestions from this website so believe it to be a faulty temp sender to the fan - is this feasable ? Has anybody else experienced this ? Could it be the 'Aero' kit restricting air flow ? (I notice that the only route for hot air to escape unassisted is via the fan shroud - is this enough ?) I'm tempted to just unplug it, but know I shouldn't ! (assume I'll get a warning light anyway...) Has anybody got any further ideas ? Many Thanks in advance, Richard.

Update - The Auto Enginuity and TekMate products do not work on a 1999 996 C4 UK Spec. :-(

Loren - All Porsche US cars do comply with the ISO standard since MY1996 - (a Federal Requirement) however RoW cars did not catch up until MY2001. That is why here in the UK, OBDII scanners are very hit and miss between MY1999 and MY2001. I've just sent the OBDII Pinout to a UK resellor of the 'autoenguinity' product in an effort to clarify if it should work. According to their website it will, (pin's 4,5,7 and 16 need to be there) but just need to confirm before I spend my cash. FYI - OBDII Pinout on a RoW MY1999 996 C4 1 - Black/Red 2 - n/c 3 - Yellow/Blue 4 - Brown 5 - Brown/Blue 6 - n/c 7 - Orange/Black 8 - n/c 9 - Purple/Green 10..15 - n/c 16 - Red/Black (confirmed as +12v) I guess the extra pins are used for Porsche's diagnostic tools. I'll update the post once I get the results back ... Thanks, Richard.

Paul - Thanks for the reply. That's positive news then as I guess any OBDII scanner should work as they all use the same protocol. If your 98 sends it, then I'm fairly confident that my 99 should.. I'm down south in Kent so a fair few miles away from your good self in Scotland ... Thanks again, Richard.