Christian's build in MA; US Exocet #148

[buildercg]

Unfortunately, my alignment appointment was cancelled due to a loud knock issue that the car developed after changing the oil over the weekend coupled with a complete loss of oil pressure at the gauge (this is after running a completely new wiring run to the dash).

I don't have the tools for measuring oil pressure (I had a REALLY bad experience with a brand new Harbor Freight compression testing tool over the weekend; don't trust their tools anymore) and I also don't have the experience to know if the knock is cam noise due to the new oil, loss of pressure, interference, etc. so I took the car to my normal mechanic for diagnosis. The knocking sound is very loud at idle and smooths out as RPM comes up.

I'm keeping my fingers crossed that the issue is simply the new, heavier oil and a bad sender.

[buildercg]

Mechanic confirmed zero oil pressure....that's a real bummer...

[gwnwar]

How did he check it.. what type gauge..
How long did you let it run before you shut it off..
What weight oil did you put in..
Did you check in oil filler hole for oil splashing with engine running..
Did you check the wiring after oil filter change.. maybe off..either end..
Did you remove the OEM gauge and later put it back on.. If so did you wrap the threads with plumbers tape
This is a No NO the thread are how the gauge grounds its self..
IF the engine is bad it would be cheaper to replace it with a good low mileage 1.6 or go to a NA 1.8 with the Flying Miata
swap kit.. Then having it completely rebuilt.. Just a oil pump @ $150.00 > $200.00 parts PLUS labor..
If you go for a 1.6 engine make sure it has 8 slots in face of crank pulley that will make it a BNC engine..
Can you post a video of the noise please..
Don't give up hope, stand back, it is not the end of the world just a little set back.. Post that noise video..

[buildercg]

My mechanic used a mechanical gauge, I don't know the brand but the guy is very trustworthy.

The car had Castrol full synthetic 5W-30 in it when the problems with pressure started; the oil never got dirty and only had 47miles on the engine when I changed it. I changed to Penzoil natural 10W-40 as the engine was getting quite noise along with the gauge problems. After changing the oil the noise became very loud at idle. I ran the car for probably 10-15 minutes (mostly idling in my driveway and the driveway of the garage) and the Miata guage didn't leave zero after changing the oil.

I was very careful with wiring. I actually now have 2 wires available as I ran a completely new line to eliminate the possibility that a bad splice was the problem.

I have not changed the gauge pod. My mechanic removed the Miata sender and used that location to measure pressure. The sender was not re-installed as I'm at the point of "rebuild" or "buy replacement". My mechanic is telling me it's a minimum of 7 hours labor for him to replace just the oil pump, plus parts. It looks like new OEM pump is around $200 from FM. It's not carried locally as far as I can find.

I've got a video...got to learn how to post....

[buildercg]

Hopefully this works.

[buildercg]

AAA brought the car home tonight.

I took the valve cover off. I'm not an expert, but I can detect no damage. Everything is very lightly covered in oil. I see three ports, two back and one front, which appear to be passageways for oil to flow. They seem the be clear. I see no debris, no scratches, and no obvious heat stress on the cams. All the springs appear to be intact/no damage and I see no heat/scratching damage on the valve caps.

I pulled the plugs and all have carbon deposits. #2 has a small amount of oil which wiped off on my finger.

Looking down into the cylinders it looks like black rough sandpaper with some glossiness. I'm guessing lots of carbon deposit in the cylinder heads and maybe some oil too. I don't have a scope. From what little I can see, they all look about the same.

If I replace the pump, I'm probably going to tear the engine completely down and replace all the gaskets as I know there's at least one minor, persistent leak and the engine probably hasn't ever been overhauled. This investigation makes me think oil is getting into #2 cylinder so it makes even more sense. I figure doing so will cost north of $1200 for the parts and tools and probably more if machining is needed.

Tomorrow I call my local used Miata shop to see if they have any low mileage 1.8L '94 or '95 engines (emissions drives the year) available. I know my current engine and transmission came from them and they deal exclusively with Miatas. If a replacement engine plus FM's conversion kit come in similar price to rebuild then I might just go with a 1.8L swap.

I've read FMs swap guide several times but it's unclear if I need to replace the flywheel and clutch. I'm sure someone here knows. If I have to swap that's obviously quite a cost factor. I also assume I can keep my existing transmission.

[gwnwar]

Get a compression test on a new engine. Depending on the mileage on new engine TB, WP, Seals or get car running and see how it is..
Good winter job if want to..You can use the 1.6 flywheel and whole clutch unit on a 1.8.. It has just a little less grab surface. If not going to race or add boost, for normal driving it will be OK..

You might have read all of these.. google "FM miata 1.6 to 1.8 engine change" will keep you reading for awhile..
Remember if/when you get a 1.8 you will need the mounts for the motor mounts, intake and exhaust manifold,down pipe.
If it comes with a flywheel take it for later use maybe..

[buildercg]

Jun 28, 2017 5:10:34 GMT gwnwar said:

Get a compression test on a new engine. Depending on the mileage on new engine TB, WP, Seals or get car running and see how it is..
Good winter job if want to..You can use the 1.6 flywheel and whole clutch unit on a 1.8.. It has just a little less grab surface. If not going to race or add boost, for normal driving it will be OK..

You might have read all of these.. google "FM miata 1.6 to 1.8 engine change" will keep you reading for awhile..
Remember if/when you get a 1.8 you will need the mounts for the motor mounts, intake and exhaust manifold,down pipe.
If it comes with a flywheel take it for later use maybe..

Starting to shop engines, just in case, and shipped price for '94 1.8L with >100k miles, no manifolds + needing new seals/gaskets/WP starts at $1200. '93 1.6L only $150 less. This is from one of the big Miata parts dealers. There are a few engines on craigslist locally I'm inquiring about. The local dealer seems to be on vacation (phone is not answering and VM box is full).

Meantime, I'll be tearing apart my engine. My goal is to get the head off tonight so I can take a better look at the pistons.

[buildercg]

So I didn't get the head off last night. I just came in from working on it after running into an issue. I was starting to loosen the bolts holding the head to the block. My manual says that it's important for the bolts to come off in a very specific order and that none of them should be completely loose until all of them have had a 1/2 turn. I got #1 and #2 turned 1/2 turn each. I tried turning #3 and socket slipped over the edges of the bolt head...dang, started to strip. So I reset carefully, ensured the socket was all the way on (double checked the socket to ensure, yes, it really is the correct size) and turned again. It slipped again. I tried one more time with the same result. Now the bolt head is rounded off almost completely...there's nothing for the socket to grab. I could drill or cut this bolt head off but most of the bolts are still tight/not loosened. What do I do? I'm trying to avoid damaging/warping the head in case the engine can be repaired.

[gwnwar]

Are you using a 6 point socket?? If I remember right it is a 12 point 12mm socket or a 13mm 6 point socket..Sounds crazy I know..
If it is really messed up and the 13 6 point tapped on down tight and held down good as you use a length of pipe on the end of the breaker bar.. doesn't work.. You could try a 12mm 6 point beat down onto it. a 1/2" drive would be good for that..
Do you have anybody that can arc a short 1/2" bolt onto the top of it.. If not maybe a welder that makes house calls..

[buildercg]

The guide I have says to use a 6-point 13mm socket which is what I'm using. This socket fits snugly on top of the bolt heads. Last night I used a rubber mallet and hammered the socket onto the top of the nut to no effect and the first "slip" and each time afterward.  A 6 point 12mm socket does not fit. I'll try a 12 point 12mm socket tonight (not sure I have one, might have to buy one). I'm using 1/2" breaker bar with an adapter to a 3/8" socket as my 1/2" sockets are all too thick-walled to fit.

I read about welding a nut on top but my welder is not appropriate (I have a cheap HF flux welder) for that nor do I have the skill. I also read that there's a tool that is designed to be hammered on to grab the head and allow for removal. Obviously, that destroys the bolt. I don't know anyone with any appropriate welder.

If I cannot get it off then I'll grind the bolt head off (that I can definitely do) and pray that the head doesn't warp.

[buildercg]

A replacement 1.6L engine is looking like a minimum $2000 investment; probably more like $3k+. I have found salvaged engines available from planet miata, treasure cost, and other places that typically cost $1250-1750/shipped.  '94/95 1.8L is running a few hundred more expensive. The engines all have >100k miles; some over 200k. All come with no warranty/no guarantee and require timing belt change, water pump, often needs both manifolds (not a problem for 1.6 but more expense if I upgrade to 1.8) and not necessarily compression tested, offered "normal wear and tear" (e.g.: needs new seals).  These issues all add up quickly to address.

The engines I'm finding locally are sold as-is (mostly high mileage needing to be overhauled) by individuals who cannot provide title documentation. There's a 60k mile 1.6L on eBay for $1000, shipped, but the VIN has been removed. Without VIN and proper title transfer documentation I could have my car seized by the state.

It's looking more and more that my option is to rebuild what I have (and hopefully I don't screw up).

[rv8air]

If you've not taken the engine apart yet, i.e., if you can still start it up, get an electronic stethoscope and zero in on the source of the noise. If you don't have one. Maybe the parts house could lend you one. What I thought might have been valve noise, was actually a rod bearing, and my DD went in for a rebuild. However, if the noise is in the valve train, you could save some money reworking the head.

[buildercg]

Jun 30, 2017 18:07:13 GMT rv8air said:

If you've not taken the engine apart yet, i.e., if you can still start it up, get an electronic stethoscope and zero in on the source of the noise. If you don't have one. Maybe the parts house could lend you one. What I thought might have been valve noise, was actually a rod bearing, and my DD went in for a rebuild. However, if the noise is in the valve train, you could save some money reworking the head.

I've already in the process of taking the engine apart. timing belt off, manifolds off, alternator off, etc.. I'll save the tip for next time. 

In my case, since I have the manifolds off I can turn the crankshaft (well, I could with the timing belt on) and see the valves opening and closing. Everything looks pretty good from what I can see but I still cannot see the entirety of the piston heads. That will change this weekend.

As a side note, with the timing belt on, I took the crankshaft though a lot of complete rotations and no oil came up to the head (I haven't drained the oil yet). Even though I wasn't spinning the crankshaft anywhere near even a normal idle, I would have figured that if I had any oil pressure at all I would have seen some come up so this further solidifies the issue as the oil pump.

[buildercg]

I got a lead on a couple of available engines locally available. Going to check them out tomorrow.