4.0cherokee

Okay I am going to try and shorten this post down a lot. It spans 5 months and 2 miata heads. Now I need help to know what to do.
Original issue.
No compression in cylinder 2 and 3
Took head to a machine shop and was told head was warped. Had machine shop deck the head and reinstalled head. Only to find out valves had no clearance after he did a valve job. Took head back to him and had him cut valves to length. Put head back on ran great for 45 min. Then car just died and had to be towed home. Found exhaust cam locked up. Front journal was trashed. It broke the cam gear bolt and snapped off the little alignment pin. Called a different machine shop and was told that the issue was original machine shop had only fixed the bottom of the head and not the top. So this is what caused the issue. So I placed an order for another head. Wait a few weeks for it to show up. While I wait I order another new headgasket. When the head gets in I install everything from old head to new one. I pulled the spark plugs from the car and cranked the car over for about 30 seconds to make sure there was oil preassure. I started the car and it ran perfect. Then after a few seconds the car was just pegged on hot. Tried to see if the sensor was malfunctioning but looks to be good. I then removed the T stat to make sure the new one wasnt stuck closed still didnt help. The water pump is new. I installed it when I did the head the 1st time so it has maybe 50 min of run time. I let the car sit for a few hours and the car still heads Hot and will barely run now. I have included a picture of the original gasket and the cometic gasket. The felpro that is currently in the car has the same holes as the cometic. The holes do not line up with the original head gasket at all. Both heads are BP4w heads.

Now my question is what do I do now. I have spent 1k plus trying to get this MSM back up and going. It has taken 5 months to get to this point. Its still an eye sore and I dont know my next step. Did I ruin another head with a headgasket?


Old on top of new

aidandj

iTrader: (5)

The cometic/felpro gasket is a 1994-2000 head gasket.

The head gasket is not the issue. Either one is acceptable. Although the 1994-2000 gasket is preferred with a reroute.

4.0cherokee

I dont have a reroute. I just put in that I had a 1999 head and ordered the gaskets. I was reading that the 01+ were different. I know the car is an 04 ,but has an 99 head correct?

aidandj

iTrader: (5)

There is tons of info out there about head gaskets

https://www.miataturbo.net/engine-pe...ication-61506/

lots of reading to do.

But I don't think the head gasket is your issue.

4.0cherokee

Yeah I read that thread before posting. I have an 04 msm. I bought the 99 head and gasket since the msm uses a 99 motor and head from what I have been reading.

technicalninja

The MSM head is a 99-00 style with the coolant passages of the 01-05 VVT head. I found an old thread somewhere (I think it was on this forum) that had the differences perfectly mapped out.
The incorrect head gasket may well be an issue.
I believe the poster at that time had to modify his MSM head by drilling 4 holes in it to use the 99 gasket.
Or maybe it was drilling a 99 to work with the 01 HG.
Look further, I wish I was better at searching and I would find it for you.
I found it 6 months ago while trying to determine if a 99 head could replace a MSM head.

curly

iTrader: (25)

The head gaskets are all interchangeable, especially for just a simple warm up and less than 45 minutes of driving.

OP, what's your coolant bleed procedure?

Savington

iTrader: (31)

Here's my guess, in chronological order

1. A Thing(TM) killed the first head gasket and head
2. Your first machine shop screwed you by taking a head that was banana'd and just decking it. Look at the head as a single piece of curved metal (which it was). The cam caps have the same curve. Now skim the bottom flat and bolt it back up. The bottom is flat, but all the cam journals are still out of alignment. That it torched your cams is no surprise at all.
3. Second machine shop was correct, the first shop screwed you. Correct order of ops is to get a fresh head, fresh head gasket, and try again. Except...
4. You never fixed A Thing(TM), which instantly toasted your second head after you ignored the maxed-out coolant temp gauge. Your new head is now warped, unfortunately.

My guess is that "A Thing(TM)" is a plugged hose, gummed up block, or trashed radiator from Stopleak or some equally awful product the PO poured into the engine. The easiest way to fix this is to replace everything that's easy to replace and flush everything that isn't. Replace the radiator and all hoses, and flush the block and heater core. Have this flushing done professionally. Get another head, use an OEM head gasket (Cometic is no better since both are MLS), and when your coolant temp gauge starts moving towards H, shut the motor off IMMEDIATELY and diagnose the issue rather than letting it melt itself down.

technicalninja

[QUOTE}. I started the car and it ran perfect. Then after a few seconds the car was just pegged on hot.[/QUOTE]

I missed this. (and botched the quote process).

Curley is right. Even if you put a head gasket with NO coolant holes it would take a while (minutes) before you would have an overheat and the temp gauge would not react in a few seconds...
It might be a simple problem. If you have the wiring to the temp sender trapped under something and shorted to ground you could have immediate gauge reaction.
Try just turning ign to on, don't start car. Watch gauge. If you have a reaction with the car off you have something grounded somewhere.

Savington perfectly described your situation. I hope this final issue is a pinched wire and he is not psychic...

I've had heads "heat treated" where they are cooked in an oven to a specific temp and then placed in a shop press and "bent" back into shape then allowed to cool in the press.
This works OK for daily drivers but I always worry about valve seats coming loose after this type of crap and would not use a "heat treated" head if a replacement straight head was available.
Hope this helps
Rick