Holy Moly!!! Look at the smoke!! [Archive] (2024)

MX-5 Miata Forum > NA/NB (1990-2005) Miata > NA (1990-1997) General Discussion > Holy Moly!!! Look at the smoke!!

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MazdaLover

13th January 2003, 18:35

On my way home from school on the Interstate, I noticed some white smoke billowing out the back of my car. I got off at the next exit (about 2 miles away) and pulled over. As I opened the door to get out, a MASSIVE amount of smoke started pouring out from under the hood. I didn't panic too much since it wasn't black smoke and I also recognized the sweet smell of burning anti-freeze (ala my old RX-7).

I watched my gauges througout the whole ordeal and both temp & oil guages read normal. I checked the oil level and it was also normal, but the coolant reservoir and radiator appear to be bone dry. At this point, I crept to the back of the car knowing exactly what I was going to see... oily radiator fluid ALL OVER THE REAR! Everywhere... from the top of the trunk to the exhaust, and all over the entire undercarriage for good measure.

I'm diagnosing it as a head gasket failure, but the engine bay makes it difficult to pinpoint the area in question. There's oily radiator fluid sprayed all over the firewall as well as most of the transmission tunnel and so forth.

I've been quoted a price of $525-$575 (minus machine shop) but I'm curious as to what is involved with changing the gasket myself. Anyone have a parts list? This way I could also change the water pump and other items neccessary that otherwise wouldn't be changed by a machanic for the quoted price. I can't find a tutorial or FAQ for this in the garage or by searching so if someone has a link or personal experience that I might glean some knowledge from I would appreciate it greatly. This would be the most intensive work I've ever done on an engine, but I've changed several water pumps, starters, oil pumps, etc. so I'm not a total newbie. I've just never worked any further inside an engine than the valve cover.

On a side note, this is the first time I've ever had a major incident in a vehicle where I didn't immediately flip out. I just waited patiently for the tow truck, content with assurance that this forum would probably have the answers I'd need. I thought that was pretty cool... the blown gasket on the otherhand... not so funny. :)

Don

13th January 2003, 21:05

Might be something so simple as a ruptured heater hose squirting coolant on the header - I'd do some troubleshooting and make sure the smoke is coming from out of the exhaust pipe before I took anything apart

Don

toenail

13th January 2003, 21:10

Sounds like head gasket failure might be a premature diagnosis based on the info you provided. Fill it back up with fluids and fire it up. You should be able to see where it's leaking at idle.

My first thought was heater hose except that you mention "oily". If the oil level was fine I'm not sure how you account for this.

Cliff Knight

13th January 2003, 21:46

Are we talking white smoke or steam? Big difference...

Smoke = coolant getting into the cylinders = something real bad happened;

Steam = leaking coolant = just a big mess and fix whatever rubber/plastic/aluminum/brass thingy blew.

Do the 1.8s have that rubber capped nipple on the rear "thermostat" housing? If so, that puppy blowing could easily account for the mess.

MazdaLover

13th January 2003, 22:32

Thanks for the help guys. Gosh, where do I start? I have to say it was white SMOKE because it was seeping into the co*ckpit from between the seats. According to a man who saw the whole thing happen ten feet away on the off ramp, the smoke was NOT going through the exhaust but rather it appeared to be coming from the transmission tunnel area. I just ran to the garage and wiped my finger inside the exhaust tip and there is NO oily residue whatsoever (can't say the same for the rest of the rear end ;) ). Let me also add that from the time I noticed the smoke, up until the time I killed the engine, the engine ran normally (no sputtering or anything unusual).

I don't remember if I mentioned this earlier or not, but there was (and still is) radiator fluid on the ground that does indeed have oil in it. This led me to think "head gasket" since I'm not aware of any other way the two could mix.

The only other detail I forgot to mention was that right before I shut her down there was a nasty "whistling moan" that continued after the car was off. I popped the hood and that's when I saw the thick white stuff blowing out from the back of the engine. I also heard/saw it boiling off the manifold, so it is entirely likely that it could have been steam, albeit VERY thick VERY white steam. And it did smell like antifreeze and not oil, so now I'm even more confused.

Should I top off the fluids and start it up and see what happens? Could this seize the engine or somehow make matters worse? Keep the suggestions coming... and thanks a million guys!

SpeedM1

13th January 2003, 22:48

Mazdalover,

The same thing happened to me two months ago. It was the heater hose going back into the firewall. I had coolant everywhere in the egine bay and underneath the car. And when I stopped at a traffic light, the smoke came into the cabin from the transmission tunnel.

Hope this helps!

SpeedM1 :)

jcolman

13th January 2003, 23:01

My heater hose busted the other night. I had nearly the same symptons as you, ie white smoke everywhere. Fill your radiator with antifreeze and fire your car back up. Look just behind the cylinder head and see if the smoke is coming from the hose that runs from the head to the heater core. If you'll find that it's cracked, you can probably fix it yourself, but it's a b***h to get at the hose connection. My local shop charged me $100 to change out both hoses.

Good luck.

Cheers
Jim

weekapamiata

13th January 2003, 23:18

I agree... had the same thing happen to me... could be as simple as the 2 heater hose in back of motor

MazdaLover

13th January 2003, 23:33

Wow! I'm feeling MUCH better about this situation now. After reading the last three or so replies, I started asking myself how so much oil ended up in the mix, yet my oil level was exactly where it was the last time I checked it about a week ago. Then it hit me! I installed the oil filter relocation kit about a year ago and didn't get the connection right the first time which resulted in a nice steady leak of oil all over the firewall and my oil pan two quarts lower than normal in less than a week. So I'm hoping (make that praying) that this whole ordeal was a twisted way for the Miata gods to steam clean my engine for me. The thing that's eating at me right now is that its about 18 degrees here in KY and I had turned the heat off many miles previous to this happening because the heater always turns my little co*ckpit into a BBQ pit in less than 10 minutes. Am I right to assume that if I had still been running the heater, it would have blown out "not so hot" air, similar to when a thermostat malfunctions? Now I'm kicking myself a little on that one, because like I said earlier, the engine ran fine without a single hiccup the entire time. Surely if you blow a head gasket the engine is at least going to sputter or stall a little bit, right?

TOmmorrow I'll refill the fluids and start it up and see what happens. WOuld you mind telling me what I'll be looking for? I assume the car won't steam until the block gets hot enough, so should I just look for coolant spurting from the back of the block or can I actually see the heater hose?

Which leads me to my next project. I'm off to the glorious search button for tips and tricks on heater hose replacement.

This forum TRULY is a life saver and has pulled my butt out of the fire on several occassions. I hope this is one of them... <fingers crossed>

canyoncat

13th January 2003, 23:58

What you have described is EXACTLY like when my 95 blew the heater hose on the firewall. I agree with the other guys. Betcha that's what blew.

MazdaLover

14th January 2003, 00:16

Okay, after some searching and a quick trip to the garage, I think I have figured it out. I've been burning oil at a fairly slow rate for the last year or so. Basically I'm burning enough to require adding about 3/4 quart of oil per 3,000 mile oil change interval. As I was studyig up for my big day tommorrow, I ran across others having a slow leak.

I'd always assumed I was just burning oil because I have nary a drop on the garage floor so it must have gone up in smoke, right? Maybe not. I keep seeing where people speak of the CAS seal leaking slowly (equivalent to the amount mine "burns" oil). Then, I researched a little further and started seeing posts about how this CAS seal is located above or near the heater hoses and that hot oil might presumably drip onto the rubber heater hoses below. I'm guessing hot motor oil and rubber don't exactly agree with each other but might actually be... DAMAGING!?!?

My latest diagnosis/reconstruction of this event goes like this:

1. CAS seal fails.
2. Oil leaks slowly onto heater hoses below.
3. Oil level slowly dips over time.
4. Oil eventually corrodes or melts rubber heater hose.
5. Rubber heater hose finally gives way this afternoon.
6. My wallet gets worried, Miata.Net saves the day.

How's this theory sound? If this sounds plausible, then I need to add the CAS seal to my list of things to do tommorrow. Now I'm off to learn about this procedure just in case its the culprit. BTW- my car has 118,000 miles on the original engine, so some of you folks might want to take a quick peek under the hood this weekend and check the condition of these hoses... it just might save you a headache.

Any idea what new heater hoses and a CAS seal will set me back? Can I pick them up at the Mazda dealer here in Lexington? I'm guessing about $60 for the hoses and $1.00 for the seal. Please tell me I'm in the ballpark.. PLEASE!!!

ML
:)

Astro in Bayview

14th January 2003, 01:05

I think a complete set of hoses (radiator, coolant and the small bypass numbers) is $69 and the CAS o-ring was $5 or $6 from Finish Line Performance (no affiliation, etc.). My CAS started leaking at around 79K and one of my heater hoses started leaking at the firewall at 85K but didn't blow. Replacing all the hoses was an all-day proposition, especially the heater hoses and the bypass hoses that connect at the oil filter housing. (I had to remove the oil filter and the intake manifold brace and the alternator.) The hoses were getting pretty inflexible, so now I've probably got another 90K miles of peace of mind.
ML, if you're at 118K, aren't you about due for a timing belt too?
There was a thread here recently about a cheap and easy CAS o-ring replacement. Was it Pops VII?
-- Kurt

MazdaLover

14th January 2003, 01:12

If you just jinxed my timing belt I'm sending you the bill! Don't even think about mentioning the original clutch either... ooops. Ideally, I'd like to replace the heater hoses for now and then replace the others when I get the time away from school.

Does anyone have a FAQ or tutorial for replacing the heater hoses? I can't find one. Also, would it be correct in assuming that oil and antifreeze aren't healthy for paint? How can I wash this off my firewall without creating a bigger monster than I've already got?

ML
:)

Astro in Bayview

14th January 2003, 03:07

Try spraying diluted Simple Green throughout the engine compartment, then quickly hose it off. As far as replacing the hoses, undo clamps with pliers or vise grips, remove. For the heater hoses, remember to cut them off at the firewall instead of twisting them off with pliers. You can easily (relatively anyway) replace the heater hoses now and do the rest later. I hope I didn't jinx your timing belt, or your clutch. Mine's original too, at 94K miles.
-- Kurt

neumann

14th January 2003, 10:19

cas o ring was leaking, dripped oil onto hose, hose slowly gets corroded over time by oil and eventually springs a leak...my friend here in town with a 94 black and tan expereinced the same hose failure...hose is about $16, o ring is $6 (quoting Mazda part prices) and about an hour of time

I'd consider springing for both firewall hoses and replace them at the same time.

Mark Leinhos

14th January 2003, 10:29

So did you figure out if it's really the hose or not? I was just thinking that if it WAS your head gasket it would be pretty obvious that there is also water in the oil (milky) as well as oil in your water. If that's not the case then it certainly wouldn't be the gasket.

Lanny Chambers

14th January 2003, 14:16

A head gasket can fail anywhere, not always in a place that lets oil into the coolant or vice versa. I had one let go on a Honda: it leaked coolant into one cylinder, but the sump and radiator remained uncontaminated. In hindsight, it had been leaking intermittently for two years before it finally prevented the engine from starting.

Things are rarely as simple as they seem... :)

---
Lanny Chambers
the alignment page (http://www.hummingbirds.net/alignment.html)
'94C

munque

14th January 2003, 14:34

From Trussville, miata heater hoses were about $35 for the pair and $5 for the CAS o-ring. You can find the O-ring at NAPA for under a dollar if you know the diameter or bring in the old one. Hoses seem to be a dealer part.

Before you go out and start buying parts, you might want to refill the radiator with 50:50 anti-freeze/water, start engine, let it idle and look for the gusher to verify leak source.

14th January 2003, 15:08

Originally posted by munque:
From Trussville, miata heater hoses were about $35 for the pair and $5 for the CAS o-ring. You can find the O-ring at NAPA for under a dollar if you know the diameter or bring in the old one. Hoses seem to be a dealer part.

If it is heater hoses, a hefty needle nose pliers or vise grips is handy for getting to the one unreachable hose clamp behind the engine. I replaced with a new screw type clamp for convenience, but others think the old spring clamp is better. After sliding the clamps away, slit the hoses for removal as they usually have shrunk too much from heat to slide off. munque just said everything I was going to say, except I'd buy a pair of needlenose vicegrips for the clamps. The job took me less than an hour, and that was because I spent 20-30 minutes looking for my needlenose vicegrips after struggling with the regular pliers. Just cut off the old ones, making sure to note how they are stuck on there, and stick the new ones on, easy.

Chris

MazdaLover

14th January 2003, 16:26

Well, I just got into checking under the hood and you guys were correct, it WAS the heater hose. The CAS seal has failed and dripped oil onto the hose and now it (the heater hose) feels like slimey jello... NO RIGIDITY at all! Looks like this is going to kill two birds with one stone... I owe you guys one! Thanks again.

ML
:)

toenail

14th January 2003, 18:23

Another happy Miata.net ending :) Please let us know how you make out with the hose and o-ring swap.

MazdaLover

14th January 2003, 19:57

Rather than start a new topic, I'll post my latest problem here. I accidentally assumed the form of a gorilla and over tightened one of the two smaller bolts that goes in the front of the valve cover and sheared the head off. Since it doesn't actually mount the cover to the block, I'm not that concerned with it but I'd still like to get it fixed soon. For the life of me I can't remember the name of the tool that I need to get... and don't say a torque wrench ;) !

Question number two: As I successfully put everything back together tonight (total job time: 3 hours/6 beers/1 nasty wound on knuckle) I started wondering if the thermostat or any other coolant-related parts could have been damaged when the hose ruptured and now need replacement while I'm feeling mechanically-inclined?

P.S. To answer your questions before you ask them, "YES" I know I need a torque wrench; "NO" I didn't over-torque the rest of the bolts (I went a nudge past "finger tight"); and "YES" I am aware that you can remove the CAS without removing the valve cover, but I figured I'd spend an hour or two figuring out how or I could just take 15 minutes and remove the cover! Cheers!

ML
:)

ralph f cooke

14th January 2003, 20:35

I assume you are referring to one of the bolts that holds the little chrome crosspipe to the front of the cam cover. If it has sheared off flush with the surface I would first use a center-punch to put a dimple in the middle of the broken bolt. Using a dremel or other small power tool drill a small hole, say 1/16 or 3/32" down the middle, next use a slightly larger drill - 1/8". At this point you should be able to use an 'eazy-out' to remove the stub of the bolt. make sure you use a proper handle for the eazy-out, they are extremely brittle and if you try to use one with a pair of pliers or a grip wrench you are almost guaranteed to break it.

Good Luck

sayonara

14th January 2003, 23:02

Originally posted by Lanny Chambers:
A head gasket can fail anywhere, not always in a place that lets oil into the coolant or vice versa. I had one let go on a Honda: it leaked coolant into one cylinder, but the sump and radiator remained uncontaminated. In hindsight, it had been leaking intermittently for two years before it finally prevented the engine from starting.

Things are rarely as simple as they seem... :)

---
Lanny Chambers
the alignment page (http://www.hummingbirds.net/alignment.html)
'94C On the other hand, the simplest explanation tends to be the correct one.... ;)

Sean

Gibson99

15th January 2003, 21:54

Things are rarely as simple as they seem... :)
agreed. my dad had a '90 v6 4-runner with a BHG. didn't have the normal symptoms except that it was losing coolant very slowly and it would randomly misfire at steady speeds on the highway. otherwise it ran great. 150k on it. and then we found out that toyota has a recall on the 3.0L v6 truck engines for defective head gaskets, regardless of age/miles. so we got new HGs put in for free. :)

Nick [thrlskr]

16th January 2003, 12:28

Posted by Mazda Lover:
I accidentally assumed the form of a gorilla and over tightened one of the two smaller bolts that goes in the front of the valve cover and sheared the head off. Since it doesn't actually mount the cover to the block, I'm not that concerned with it but I'd still like to get it fixed soon. For the life of me I can't remember the name of the tool that I need to get... and don't say a torque wrench !
Get a TORQUE WRENCH!! :p I can't tell how many things I haven't broken since I got mine!

Nick