Engine Rebuild Time is Near
As some of you may recall, I replaced the oil pump in my '96 just before Christmas. I was experiencing a variety of symptoms that pointed to the sticky relief valve problem - starting shortly post-Hallett, in October. I opted drop the subframe and just replace the pump - hoping that would be sufficient.
My oil pressure issues are gone, but the engine is making a noise that sounds like a bearing may have suffered the effects of the oil pump problem. RJ and Gary have both opined that it sounds like a rod bearing. Blackstone says the only abnormality in the sample I sent them was high aluminum. I'm concerned that the high aluminum is from the cam journal bearings and wonder if the head is damaged...
The car is still running well, making good power. No oil consumption or leaks. Car has about 83k miles, new oil pump, TB/water pump were done at 66k.
So what next?
Can somebody PM me John Day's contact info?
Thanks,
Craig
The rest of the story - LONG
Quote:
Originally Posted by
Titus
Story?
PO is from Austin, and early last spring (while he still owned it), the car had an episode or 2 of clatter/low oil pressure for a couple of seconds at startup. John Long looked at the car and said it might be early sign of oil pump failure, or perhaps "crud stuck somewhere" but couldn't reproduce the noise. John's plan to fix it was to pull the engine, replace the oil pump, check everything out - which of course would be expensive. PO drove the car for another month or so - no clatter, no low oil pressure - but the spectre of looming engine repairs led him to trade it in on an RX-8.
I bought the car in May from a dealer in Austin. I found the car to be in great shape. It had the working OPG retrofit, the folding front license plate bracket, an NB windblocker, and Tejas Miata window decals, so I knew it had been an enthusiast's car. I worked out what I thought was an excellent deal on the car. (Perhaps now it was only a decent deal - but I still don't feel like I got totally screwed).
I got on Tejas Miata's forum and discovered the POs posts about clatter, John Long, RX-8's and such. I contacted the PO and learned quite a bit more about the car and its maintenance history. Recent TB/WP, Magnecore wires, upper and lower shift boots, Redline trans and diff fluids, recent rear window - all the stuff you'd want to do to an car with unknown history. He even sent me a box of parts he still had in his garage, including the boot, ashtray, rear cockpit brace, Haynes manual...
Between May and October the car showed the low oil pressure at cold start and accompanying clatter an a handful of occasions, and I almost wrote it all off as lifter clatter or something else. Well, this fall, the problem began to get worse. I spoke to John Long, and his recommendation was the same - replace the oil pump.
Based on my conversation with him and some reading on the pointy board (and the fact that I wasn't paying someone else to do the work) I decided to just replace the pump and see how it goes.
Well - it goes in the direction of a more serious teardown.... I'd prefer to not have to spend $1k on a full rebuild, but I'm also not sure oil pressure problems didn't cause some damage to the head at the cam bearings. As I mentioned - Blackstone found Al in the oil.
Although rebuilding a Miata engine at 85k isn't common, it's not totally unheard of either. Iain has his redone at 95k, and there are a bunch of examples on the pointy board of people with rod bearing wear requiring a bottom-end rebuild - many due to the oil pump failure on '96 and '97 cars.
So while I'm bummed at the prospect of spending $500 to $1000 on the car without a performance boost, I still have a great Miata. Those of you who have seen the car know it's very clean. The paint and interior look great. It's never been wrecked. It's been reasonably well maintained. I've spent a few hundred on the suspension and I think it handles great. When you drive a 10 year old car, sometimes you have to spend a bit on repairs. Even with the cost of an engine rebuild, I doubt I could end up with a car as nice as mine for what I'll have in it...
As for Sharpie's comments, I believe John was right in his initial diagnosis and he was straight up with me when I contacted him. Had the PO or I replaced the oil pump at the before the problem got worse, I might not have to rebuild the engine. If I were in Austin, I'd likely be having his shop do the rebuild.
Craig
