"Costs Associated With Major Maintenance Intervals"

Contributed By:Dan Banks

I bought my 1990 300ZXTT in September, 1990 which now has 96,500 miles (am planning entry into daily driver category at York, Pa.). My car remains almost completely stock and is the only Z- Car I've owned. I can share the following thoughts/recommendations for those interested in the purchase or maintenance of one of these fine cars as the mileage builds.

I have virtually all my maintenance done at Nissan dealers and prefer smaller ones. They have all been invariably polite and good natured, recognizing in me an "enthusiast" having an "intense" relationship with his sports car... Unfortunately, as we have all observed from the charts of model year versus numbers sold, after 1990 and 1991 fewer and fewer were sold. The Twin Turbo iteration in its final years sold in true Ferrari numbers. So the service departments have not seen many and yours may be the first they do something complex on. I prefer to attribute my need as an owner to pre-identify wear limited components for removal and replacement simply to Nissan's service department's (outside of the larger warm climate Z markets) minimal experience. In other words, you as the owner need to know what to have done. The following will be helpful for owners contemplating the 60,000 mile maintenance:

Nissan mandates that the camshaft timing belt be removed and replaced at 60,000 miles. A local performance shop near my home here in New Jersey had a TT wherein the belt snapped while the engine was running. They advised me that the engine damage was substantial. During the 60,000 mile maintenance, it takes 5 hours of labor to get all the way down to this belt. Many other components are uncovered which can also then be easily removed and replaced. The issue as the owner is how long do you plan to keep the car, how much peace of mind do you want, and can you afford the extra few hundred dollars for the following parts. Current "wisdom" I have collected indicates that parts exposed with the belt which cannot be expected to go another 60,000 miles should be replaced at the same time. This rather than having them fail later requiring the same 5 hours of labor you just paid for to get the belt out to be again repaid.

Along with the camshaft timing belt, it is advisable to remove and replace the 4 camshaft end seals, the crankshaft end seal (a different part number but identical in dimensions to the camshaft end seals), the camshaft belt tensioner, the water pump, both radiator hoses, and the 3 accessory drive belts. In my case, I had found out only about the camshaft end seals and had nothing else replaced at 60,000 miles. About 30,000 miles after the the 60,000 mile major maintenance was performed a squeal developed from the front lower center of the engine after it warmed up and I suspected the water pump. The water pumps are not expected to go 120,000 miles. If one seizes up on you it is conceivable that it could throw off metal slivers that you don't want in your coolant system/radiator. Also, as I understand it, the pump is driven by the driven off the center accessory drive belt and if the pump seizes or drags friction could deteriorate and/or destroy the belt. The camshaft belt tensioner is another component that wears out and starts to make "bad bearing" noises. For peace of mind, I simply had all the above components removed and replaced all over again half way to the 120,000 mile interval, re-paying the previous labor. Nissan's cost on the above named components is $450 and they will want 8 to 9 hours of labor. The only thing fancy I did was to replace the lower rubber radiator hose, which is a 2 1/2 foot long tube, with the Stillen aluminum lower hose designed expressly for the Twin Turbo. (See their new catalog). The lower hose is on the low pressure (sucking) side of the water pump and under extreme load/high speed performance may cavitate. I don't do that with my car and indeed the original ran the 90,000 miles and emerged in good shape. But I figured the aluminum hose would have a higher burst strength and, being 2 1/2 feet of aluminum, should have a marginally positive effect on cooling, too. It costs about $110 compared to the rubber hose which is around $40.

A note on the factory turbochargers. The bearings in the factory turbochargers can be expected to begin to leak anywhere between 60,000 and 80,000 miles, I'm told, depending on how the car was driven. For me the symptom was that after letting my car sit for a week (I use it only for weekend driving and almost exclusively interstate), upon start up and after about 3 minutes, a nicely embarrasing cloud of blue oil smoke would emerge from both exhaust pipes for about 1 minute or so. No more oil smoke after warming up on the first start, no apparent oil consumption overall. The symptom would reappear only after the car sat again for a week. It is my presumption that the turbo bearing seals were simply seeping oil which puddled in the exhaust side hot section and smoked off on the first start-up. I was advised of another method to tell if the turbo seals are going. Take the car out onto a highway and clear the road in front of you. In second gear apply full throttle to bring the boost up to its redline. Look in the rear view mirror to observe a cloud of oil smoke (having first made sure that the road ahead is clear because you are getting there very fast while looking the wrong... well, everyone gets the idea). If you see the smoke and the car has high miles, suspect the seals. Opinions vary on how long one should/can run a turbo car with such a problem. In my case, my car was purchased with Nissan's then "Gold Plan" warranty which was 100,000 miles and 72 months and believe it or not covered the turbos, items that Nissan must have known wouldn't run that long. At 82,000 miles and 70 months into my warranty, a small Nissan dealer who had never done the job before pulled the engine and removed and replaced the turbos for a single $25 deductible. That was 13,500 miles ago and the oil smoke problem has not re-appeared. As an aside, Nissan dealers who know about the wretched job of removing and replacing the turbos may not be very enthusiastic on this one if you are under their warranty. The first dealer I took the car to, a large local one, I believe knew what the problem was but dissembled to me about it. Well, in all fairness, it took the smaller shop 4 men and 22 hours of labor to do the job. The company that holds the Gold Plan warranties allows only 11 hours of labor to be paid to Nissan while Nissan's service schedule book allows billing a customer 15.7 hours to remove and replace the turbos. The parts package of both turbos with all new oil lines, studs, nuts, etc. ( a total of 35 parts for each side) costs $2400. Figure on another 15.7 hours of labor at whatever rate your dealer charges. People who own upgraded performance Twin Turbos indicate that the replacement is relatively a straight forward affair but time consuming and best done with the engine out of the car. Nobody seems avers to having a Nissan service department do it if you haven't bought performance turbos from an established shop.

A popular auto magazine did a review of the 300ZX Twin Turbo and remarked that it was a great car (as we all know) but that one should own it for the first 60,000 only and then get rid of it. If you are looking at one of these that has rung up such mileage, if you cannot confirm that the 60,000 mile major maintenance was done right, if the car still has original brakes, clutch, exhaust, and turbos and you want to keep it running and looking super fine, plan on spending a pretty fair bit of change on it. A real maintenance fanatic can sink $8000 to $10,000 into such a car buying only stock replacement parts for components that are at their wear limits. High performance after market parts such as the exhaust, turbos, clutch etc. don't seem to cost much more though and you can easily have yourself a 400 HP version!

Watch out for the front wheel bearings. I have replaced mine twice. If they go (they make an arrythmic loud metallic rapping sound that is directly identifiable with wheel rotation) get to them immediately. If the wheel goes out of round on its bearings it will hit the ABS sensor, immediately garbage it (2 times for me) and that sensor is a $900 part in itself.

Virtually all the above maintenance was, for me, covered under my warranty. Wheel bearings, 4 sets of brake rotors (I had one of the early I-warp-right-now equipped brake rotor versions of the car), the air conditioning compressor, 2 ABS sensors, and the turbochargers. Probably all added up, the warranty coverage over the past 6 years came to at least 50% of the original purchase price of the car ($31,500 plus $1000 for the warranty). Just another reason why Nissan isn't selling these here anymore, I suppose.Including the inevitable $1200 tires every several years, I would recommend a prospective owner plan on budgeting $3000 a year over and above gas, oil, and insurance to own a post 1990 Nissan 300ZX Twin Turbo after it hits middle age. But, hey... the competitive Porsche 911, Lotus Esprit, or Ferrari not only costs 3 times as much to buy to begin with, but would, I suspect, need a lot more $$$ to keep in as good shape over the long term. And why buy some other Japanese sports car instead of the best?!!! I hope this has been helpful.