Rafa

iTrader: (22)

Hey guys, here we go again!

As the header says, I suspect I have a blown head gasket. Symptoms: a lot of coolant being consumed (had to refill the radiator after only using the car for 2 days with around 1/4 of the coolant container). FWIW, my car's been running way too hot. I already ordered and I'll be receiving Emilio's new coolant reroute system next month.

Now the questions:

1.- How do I know for sure it's the head gasket?
2.- If indeed that is the case, what do I have to buy besides the gasket and what can I do with the head once it's out?

Thanks,

Rafa

johndoe

iTrader: (5)

compression check. If two adjacent cylinders are low the gasket could be leaking there. look for coolant in the oil, oil in the coolent.

Rafa

iTrader: (22)

Thanks. At least I know for sure I don't have oil mixed in the coolant. I'll check the other way around.

johndoe

iTrader: (5)

As far as i know these are all possible symptoms. You don't have to have them all, it depends where the gasket has a leak.

Braineack

iTrader: (62)

if your vacuum low too? do you idle at something like 43kPa?

Toddcod

iTrader: (8)

Since there is no oil in the coolant, drive the car and see if the oil is creamy. if so water is in it.
After it sets all night watch your exhaust when you start it. Some steamy look is ok when it is cold out side. but you will know it when it is steaming out the water in the head and exhaust. It will only steam for awhile, untill it gets worse or won't start.

Sometimes you can see some water coming out of the pipe.
It could be your radiator cap not holding pressure. Has happened to me. Cheap try. Sometimes works.
Once it took two months of the same thing for me to see enough water to straight pin point my water pump was leaking.
Could just be the radiator causing to car to get warm and create enough water pressure to overflow out. This happened to me last year. I had the radiator boiled out, still over heated. Then replaced everything, just to end up replacing the radiator with a new one. It fixed it.

Rafa

iTrader: (22)

Hey brain, what's up? What's happening with your car? I want to hear some good news coming from you soon. I can extend you an invitation to visit anytime you wish but if you were to drive my car I'd get nervous! :gay:

My vacuum reading is indeed too low ever since I installed the turbo I'm getting readings between 20 and 30 most of the time. I asked around locally but got nowhere fast. About the idle; 43Kpa? I dunno. I can only say that I can't drive the car with the a/c on because it stalls when the compressor starts. Chad already told me that my car's ECU is controlling the idle so I guess you're also right about that.

The thing is I'm not seeing any coolant-oil mix. FWIW I did have a coolant hose blow off about 6 months ago and not only did I get the temp gauge all the way to the right side but when I was finally able to stop the car I also had some serious smoke coming from the engine.

I'm pretty sure I've got a blown head gasket. I just didn't want to accept it before! :gay:

I'm not looking to invest on a new head or something expensive. I just need the complete list of parts I'll be needing. You know how it is; if I take my car to the shop with any part missing I won't see it for 2 months

I've read some posts about some head work such as changing cams as Ben is doing but I'm pretty sure there's no one locally with any knowledge. Some say they do but as far as I've seen: bullshit.

Thanks,

Rafa

Rafa

iTrader: (22)

I've seen some water coming out of the pipe. Regarding the radiator; after the mishap I mentioned I bought a PWR radiator and the FCM fan shroud. The radiator has a high psi cap.

I'm not seeing any bubbles in the coolant.

I will check next time I start the car in the morning. FWIW 65* is cold here!. I've been checking my mirror for the last 6 months and I don't see any smoke coming out. If you asked me I would say that my engine block is fine and has not suffered any ill effects yet but what do I know?

I'll check the water pump but I changed it about 8 months ago along with the timing belt.

thanks

samnavy

iTrader: (7)

Check out these threads... I just went through the whole head gasket thing:
https://www.miataturbo.net/forum/showthread.php?t=14471
https://www.miataturbo.net/forum/showthread.php?t=14714
https://www.miataturbo.net/forum/showthread.php?t=14714

Do you now why you blew it? Were you running high boost?
How hot does the car normally run?
How many miles on the engine?

You might have a warped head, as I determined I had. If that's the case, you can simply have the head planed flat without removing the valvetrain... or you can have the head rebuilt and do a mild port-polish job. A remanufactured head is about $350 with a core swap... but it comes assembled, so any machine work is out at that point. But unless you're talking about getting into some serious boost and trying to make 250whp easier to achieve, headwork might be more trouble/$$ than it's worth.

Basically, just remove the head and take it to a machine shop to make sure it's perfectly flat. Then use a precision straight-edge and a feeler gauge to make sure the block is flat (it probably is), then scrape all the leftover gasket material off the block, clean it with acetone. Buy a new headgasket and re-install.

Other people may say that your head-studs have stretched and you need ARP's... which are about $120.

Rafa

iTrader: (22)

Ok Sam thanks. Great info there btw. A couple of questions if you don't mind:

1) Scott showed this link: http://www.boostedmiata.com/pdfs/servicemanual.pdf
but I couldn't find the manual. Were you able to download it? where can I get it?
2) from bryantaylor; quote: "copper spray the gaskets before you put them on for a little extra peice of mind. i copper spray any new gasket before i put them on and i have never had a problem with leaks". could I get some additional info?

Perfect links btw!

Let me answer your original questions:

1) Always had a cooling problem since the first time I drove the car after buying it. It had 59,000 miles on it and it's a 96. It wasn't boosted at that time.
2) I love the way the car normally runs. If I ever get it to work at around 195-200* I'll be thrilled.
3) Engine has 64,000 miles now. 14 months after buying it.

Conclusions from your links:

1) Buy the head gasket and a set of ARP studs.
2) Do a leakdown test (or 6 or 7 if I follow the advice given!)
3) take this opportunity to remove any carbon from the piston heads.

Many thanks,

Rafa

samnavy

iTrader: (7)

The manual comes up fine for me when I click the link.
I know nothing about copper spray.

You will definitely need a new head gasket.
You might also want a new intake manifold gasket as that one doesn't respond as well to re-using as the exhaust manifold gasket.

I have no idea how you can tell if your headbolts are stretched... but if they are and you re-use them, I don't think the head will seal properly. ARP's aren't cheap, but you'll never have to worry about them.

I think you really need to remove the head and take it to a machine shop so they can tell you if it's within spec or not as far as being flat.

You may indeed have simply blown the gasket, but that might let extra heat in between the head and the block and cause a warp.

Braineack

iTrader: (62)

its dead and im looking for a new one :(


the reason i ask is because you have a MS, so idle it and tell me the kPa reading. it it's not like 35kPa and more like 45kPa, i'd say its a head gasket. Does it idle rough, but run fine?

you have all the symptoms of a blown headgasket. there doesn't need to be any oil mix:



both the coolant passage blew and leaked straight into #4. no oil mix, overheating, bad idle, low vacuum, loss of coolant.


do a leakdown test. you'll pinpoint the problem right away.

Rafa

iTrader: (22)

Ok thanks. Hope I did not offend you with the driving remark. If so, sorry

I'm pretty sure I've got a blown headgasket. Lucky me I found I had one from when I bought the complete set not too long ago. I'll change it tomorrow.

About the leakdown test; I've asked before about it and was told by my mechanic that they lack the tools to do them. I'll read something about it tonight and see wtf he's talking about.

One final question: I just spoke with him tonight while he was giving me a ride back home and he asked me whether I would like my head ported. He's getting a new dremmel tomorrow. Is it worth it? I was planning on waiting to do it in a couple of months when I buy the ARP studs.

Thanks,

Rafa

johndoe

iTrader: (5)

he can't do a leakdown but he can port your head?

Rafa

iTrader: (22)

Yeah, it's not that he can't do it. We spoke about the leakdown test in some depth earlier and I understand his reasoning. A lot of his customers don't like the actual results.

It's ok; we'll do both a compression and a leakdown test even if I have to read and inform myself before I proceed.

About porting the head; I trust him but I'm not convinced about doing it. The problem down here is not whether you port the head or not; it's more the potential down time without a car if something goes wrong.

cjernigan

iTrader: (13)

His customers don't like the actual results because the leakdown shows problems that the standard compression test doesn't. That's why they're important to do, they pinpoint problems that you couldn't see otherwise.
I wouldn't bother with getting your head ported Rafa you've spent enough money. You need your car up and running more than anything.

Rafa

iTrader: (22)

+1. Any threads about how to go about a leakdown test and tools needed?

Thanks

p.s. never mind I found a thread by dow.tom. Thanks

cjernigan

iTrader: (13)

This tool : http://www.harborfreight.com/cpi/cta...emnumber=94190

You're injecting air into the cylinder and watching how much and how fast it bleeds off. So you need a tester and a air compressor.

cjernigan

iTrader: (13)

Here is a good general How To. http://www.type2.com/library/engineg/leaktst.htm

Rafa

iTrader: (22)

Thanks Chad. I can get my hands on an air compressor. I'll have to check around locally to see where I find the tester.