lymon

between 9 to 12 bar max 1 bar difference between cylinders

>I think its the intercooler as it was coming from the front passenger side must have been the radiator overflow tank that sits behind the IC. Keep a close eye on the coolant level in the radiator ! > egr valves which are located inside your wings those are the AIV's ...the EGR sits behind the engine. -Eric

try swapping the radiator cap with another one (one that is known to be working good) and see if the problem dissappears. If not, the system is building up pressure because of an airlock, which can be caused by a small leak in one of the coolant hoses or a small leak in one of the headgaskets. -Eric

there are drain plugs on the block as well, but these are a bit hard to reach with the engine in the car. Both are near the L+R engine mounts on the front side of the engine. One sits behind the AC pump, the other one sits behind the alternator Easiest is just to drain out as much coolant as possible (remove radiator), put some pressure on one of the coolant pipes to get most out of the block.

it's supposed to do that. The main fan of the Zed is driven by a socalled (oilfilled) thermal fan clutch. On this clutch is a small bi-metal thermostatic coil that will sense the heat from the radiator and engine and activates or de-activates the clutch accordingly. Once the engine (and radiator) starts to radiate a certain amount of heat the clutch starts to engage to provide maximum cooling and once the engine is still cold or at normal temps, the clutch is disengaged for the most part. On a Zed the clutch should start to engage when coolant temps reach approx. 90 degrees Celcius. You should hear a clear blowing sound coming from the fan (the car should start to sound like a giant vacuum cleaner) It usually also makes this sound when you start your car after it has been standing still for a while, but the clutch slowly disengages once the oil in the clutch has warmed up a little. If you can't hear your main fan while the engine is hot, the clutch is not engaging/functioning (common problem on Zeds) and it should be replaced. -Eric

The link is the electronic version of the 1990 service manual. I have 6 Nissan 300ZX service manuals (from 1990-1995) and in all manuals it says that if the block doesn't need resurfacing, the max. limit for the heads is 0.2mm eg. attached is the same section taken from a 1995 manual Theoratically you should be able to go beyond the 0.2mm limit using (thicker) metal headgaskets, but I never tried it myself.

As a mechanic you should know you have very little playroom with heads of most V6 engines ? the limit is indeed 0.2 mm and if you need to skim 0.1mm of 1 head, make sure you do it to the other head as well (even if it doesn't need it) if the head(s) is over this 0.2mm limit you can basically bin it. -Eric

don't under-estimate wiseco pistons. ... Wiseco, Prox and JE (another very well known producer of high performance pistons) are all owned by the same company !

Also look for (deep) scratches/damage on the leaking camshaft(s) itself. I've seen this before and in my case it was because someone pryed out the old seals a bit too enthusiastic and damaged 2 camshafts in the process....result: car needed 2 new camshafts to stop the leaks.

most central20 chips I have seen are actually very well designed chips, but a little bit too aggressive for European Fuels. Central20 chips go up to 27 BTDC at full boost (midrange RPM's), but are also very rich (AF-ratio of 10.5:1), where eg. JWT doesn't exceed 20BTDC at full boost with an AF-ratio of 12.5:1 You can still use the Central20 though by retarding the timing 3 or 4 degrees and don't exceed 12-13psi boost -Eric

It doesn't make much sense to disconnect just the engine ECU and leave the other 4-6 ECU's (ABS/HICAS/AIRCON/AT/CC/FUEL) connected...

Nissan partnumber for the bolts: 08044-4501A (same as for the 350Z calipers)

>> Why do so many aftermarket turbos fail when the OEM ones typically do 70-100,000+ miles ? In my opinion it's because many of these upgraded turbos use rebuild cores (to keep the costs down) and I have NEVER heard anything positive about the longlivety of turbos with rebuild cores. turbos that were rebuild using brandnew Garrett cores (only the shells are re-used) don't seem to have this problem -Eric

could be a small leak between turbo and downpipe/precat (usually the gasket), which gives a sound which can be described as ticking/blowing when accelerating and also causes a drop in performance. Another side effect is that the O2 sensor-readings for the side the sounds comes from stays at a low voltage most of the time. (can be checked with a conzult) In some cases it can hardly be heard from outside the car, but only when sitting in the car or when standing/laying under the car while someone revs the engine. -Eric

>> I've heard the VG30DETT is a non-interference engine WRONG ! most toyota engines are non-interference, but all Nissan VG/VQ engines are interference engines Although, if the belt breaks the valves will revert to a safe position automatically , which is fine at low revs. At high revs usually the valves won't have time to revert back to their safe position and you'll end up with a lot of damage.

Zeds and snow/ice don't mix (IMO) and normally you end up doing 360's all over the place :D Although I do drive my Zed during the winter at times it's not something I can recommend. If you live in an area with mountains/hills, it's even worse.

>> Has anyone done this? I did this on a Zed once and for a LHD car it's fairly plug and play. >> the indicators are on the left hand side of the steering wheel like most European motors. This correct? Yes correct, but just look for one from a RHD car and you'll be fine. All Zeds that have airbags do have the lever for the CC, so also the Jspec and UK ones.

in most cases it's not the belt that fails or needs to be checked but the tensioner, idler pulleys and/or pulley studs are the weak spots. unfortunately there's no easy way to check these other then listening for scraping sounds and squeeks coming from the timingbelt-area -Eric

>> Oh shit, I gave her a good thrashing today and now I seem to have a tapping Did you check the oil-level ? and, did oil pressure drop ? if it is low, then there's a good chance a big/small end has gone. ..sounds like a rattling sound which can be heard best between 2000-3000 rpm. >>can I get the pistons out the bottom of the engine with the crank out or do I need to take the heads off? if the sound gets less or disappears when disconnecting a particular coilpack it's a small end for that particular cylinder.If it's stays the same no matter what coilpack you disconnect, it's most likely a big end. Small ends can be replaced with the engine in place and by dropping the subframe and oilpan (although the crank needs to be undamaged) Big ends are best replaced with the engine out, the same is for when the crank is damaged and needs to be replaced/regrinded. -Eric

engine number can be found on a small tab at the back of the engine (look down at the back of the drivers-side cylinderhead). Is normally very hard to read because of rust/dirt. -Eric

what do you use to accurately measure the water temperature with ? since the stock gauge is close to worthless. Zeds are notorious for overheating (even with brand new or rebuild engines) and it doesn't take that much to warp one or both heads. Also were the shorter head bolts put at the correct locations ? (there are 7 long and 1 short bolt per head) ...if you didn't then most certainly this is the cause of the leaking headgasket(s). -Eric

could be the torque converter.

>. the most powerful zed he heard of was 1200bhp was probably one of these: see some more interesting pictures here: http://twinturbo.net/net/viewmsg.aspx?forum=general&msg_id=1564836 another 1200+ rwhp Zed was made by escort racing in japan: http://www.escort-jp.com/

Also see if it makes any difference with or without the filter...it might be dirty

was the little filter installed into the (boost)line to the unit ? or is the line squeezed (bent) in any way ?