Skryblz

WHHHYYY? Or better yet, what CAUSES a headgasket to blow? Bad cooling? Blocked passages in the block? Warped block in general?

I need to figure out how and why this is happening, and whether fixing it again is worth it. Car is a 1995 Civic LX with a D15B7, 159k miles. I bought the car with 118k, with one previous negligent owner. After I did some normal maintenance and a tune up, it was driving great with near 40 MPG highway.

At 128k the headgasket blew. Temp gauge was pegged before car shutdown, milky overflow tank and a blown out radiator. I do the whole headgasket job as per manual instructions, including having the head/rockers/cams all checked. There was minor scoring on the cams, but the head was still straight and checked out OK; shaved off like .004. All new OEM waterpump, timing belt, etc, everything recommended. Car is driving again, hurray!

~137k the headgasket blows again. I read some threads, and realize its common for D15B7's to do this after a previous blown HG unless you go to an OEM MLS gasket (D16Y6 I think? not sure, was a while ago. Was same shape as my D15B7). So, disassemble, RECHECK the head, still OK, and use the OEM MLS. Car runs great again!

Now ~160k it just blew again. I was having acceleration issues the past few days, and I thought it was my fuel pressure. Drove ~ 5 miles and the temp gauge had gone to the 1/2 way mark. I get home, am about to replace the fuel filter + fpr along with check the fluids. Well, it's all oil again The overflow tank is just a thick mass of oil, barely any radiator fluid in there. Toast.

After every head gasket I pressure tested it ~100 and ~1000 miles later, was in spec across the board.

I don't want to do another head gasket on this car, but I'm salty having JUST spent ~$230 on cap/rotor/plugs/wires and fuel filter/fpr/o2 this month.

JDMequalslife

sounds like the block might be warped

burnoutboy

iTrader: (22)

Remove the head and check the block for flatness with a precision flat edge and feeler gauges. More than .004 variance is bad.

Additionally make sure the block and head surfaces are 100% clean (SPOTLESS)

If at all possible use new head bolts or get ARP studs.

Clean and chase the threads in the block and on the studs, and lubricate the studs properly to get an accurate torque reading.

Make sure you're torquing the bolts in the right sequence and in the right steps for your application per the manual.

TomCat39

Also did you use the after blown head gasket instead of the regular replacement head gasket?

If you follow this link, you can see there is two gaskets available, one for normal replacement and one for a leaky replacement:

http://www.autopartsway.ca/PartList..../pagenum1/tabS

I believe Honda OEM has the same thing with their OEM gaskets.

Skryblz

I did not realize there is a leaky replacement recommended as well.... I'm sure mine was just a regular replacement both times, along with regular head bolts.

After the first one blew, I did use a straight edge across several points in the block and there didn't seem to be any issues. If I decide to keep it I'll make sure to recheck it again.

deschlong

iTrader: (8)

94EG8 (mod on here) insists that after a D15B7 hg blows, the engine is a goner. I defer to his considerable knowledge and experience.

TomCat39

I dunno, when I bought my hatch they had replaced the head gasket due to it blowing on them. Had a nice MLS gasket and looks like upgrade head bolts.

Motor had a mild knock so I went and swapped it out but not before doing several Italian tune ups and having a ball with it. Motor still was running good, just the mild knock was bothering me.

I think the "leaky gasket" replacement with the service bulletin and the new head bolts is basically a Y8 mls gasket with stronger head bolts. Also willing to bet the TSB procedures for the replacement ups the torque on the head bolts to be more in line with the Y8 or Z6.

Then again, could be why they dumped the car 6 months after replacing the head gasket. They got 6 months out of it, and I got 6 hard months out of it before I swapped in the d15b7 I got in it now that has it's stock graphite gasket. And it was still running pretty strong. *shrug*

eghatch9295

iTrader: (1)

94eg8 is totally wrong. i have personally fixed a few successfully, including my daily which has 30k plus miles on a h/g job that i did when i bought it. i think that mindset comes from a few years ago when motors were plentiful and the b7 was considered a throwaway engine

deschlong

iTrader: (8)

.... kinda is, still, innit?

TomCat39

Dunno, with the rising gas prices been seeing more and more people go for the economy cars. And I've noticed a spike in price on these older Hondas with econo boxes in them.

Used to see them for a grand or less, lately 300,000 K EG's are 2200 or more with "great gas mileage".

Another bad thing out here in BC, is Ralph's used auto parts was bought by a US based company so now any engine you have to pull and is a crap shoot. Before that, they ran it for 40 minutes to be sure it ran good, no smoke and compression tested all the cylinders before they went onto the sale shelf. If it failed anything it was scrapped. It was before the sale to the US company that I found my current B7 with 200 psi on all 4 cylinders. All the rest of the B7's had variances and highest was 180/160 motor. Now though.... pull it from a non running car and pray it works.

So motors aren't as plentiful in this area like they were even 2 years ago.

eghatch9295

iTrader: (1)

OP- id check out your block.

tony_2018

Check block, I question if you drove it to the point that the car shut off on you. If so than there's a possibility that the engine is warped. Get a straight edge, order one from Amazon, and follow the HELMS manual to correctly check the head and block for warpage.

EDIT: I wanna add that you might wanna check your water pump and thermostat. Also your coolant can also be to blame. Word of advice "HONDA FTMFW". And I mean for every part you need down to fluids. I'm suppose to flush mine out but its been 3 yrs and still doing good. That blue **** is the ****.

Skryblz

I just ordered a straight edge. I really was only planning on keeping the car ~2 more months... so I might just do what I can to get it running and then trade it in!

As far as the HG goes, should I get an OEM Y8 MLS one like I did before? Or go for that special leaky gasket as recommended by TomCat? I bought new head bolts after the 1st blowout, and reused them the 2nd and 3rd times (after running a die down the threads and cleaning the block threads). I know I probably shouldn't re-use them again, but... well, can I?

I'll be thoroughly cleaning the radiator and water pump out, and getting new fluids of course.

Besides a straight edge, is there anything I can do visually or physically to check my block out? Replacing or rebuilding the bottom end isn't worth the time and money for this car, so unfortunately I'm stuck with what's in there :-/

TomCat39

Get the leaky gasket one. The reason being is it's probably a bit thicker so won't need the super smooth RA surface finish the Y8 gasket does.

Hondapartsnow shows the regular gasket is made by Ishino:

6 12251-PM5-S02 GASKET, CYLINDER HEAD (ISHINO GASKET) CAN 1 $83.27 $59.95

And is twice as much as the same one on autopartsway.ca

US side autopartsway.com has the leaky Ishino head gasket for 61 bucks.

I believe you have to go to the dealer and get the head bolts they mentioned for the leaky replacement. Autopartsway doesn't offer the OEM bolts, just OEM "quality". For this I'd want OEM.

An unfortunate thing is the TSB here on honda tech isn't complete and you have to have a subscription to alldata to see the rest of it:

Actually found the TSB here on Honda Tech. Posting it for you. Sweeeetness!



It sticks to the 49 ft-lbs. Good to know.

deschlong

iTrader: (8)

About the only aftermarket bolts you should consider for a head are from ARP, plus they are generally OK to reuse, unlike OEM ones which the general consensus (it seems) is to not do this.

TomCat39

You know, was just looking through the FSM on the D15B7 and I can't find where it says to replace the head bolts. It only says to use new gaskets and to oil the washers and threads of the head bolts.

I guess if they don't show signs of stretching they can be reused?

eghatch9295

iTrader: (1)

yes, they can be reused. i usually do a 3rd step at 52 iirc just to be sure. my current daily is on reused oem bolts.

Skryblz

Got the special leaky gasket in yesterday.. started tearing into it today.
Well, I get everything off the head except the head bolts.
I get my ratchet ready to take off the first head bolt aaaaand it's barely finger tight -.- Like, no resistance to loosen. This was bolt #1 in the picture above.
The next 5 or 6 spreading outwards were just snug. Only ones that were actually tight were the farthest outside 4..... AAAUUGGGH!!

It must have gotten loose enough to let the oil pressure push tons of oil over into the coolant chambers, which kind of explains why my oil still looked clean. Just the coolant was fubared.

I ended up switching them anyway and stepping them in the order TomCat posted, and I felt the extra 3 ft/lbs wouldn't hurt too I had gone that far, might as well just finish it off right. I got most of it together, will finish tomorrow morning.

My block checked out pretty OK, I checked it like Hayne's suggested and couldn't find any great discrepancy. Time will tell I guess.

Just have to do a real good water flush of the whole system now and fill up the fluids. When should I recheck the torque's? 1000 miles? Earlier?


I don't know if anyone has used this gasket before. It was pretty beefy, thicker than the Y8 MLS gasket. Here's a few pictures.

It's 4 layers total. 3 MLS style, and 1 fairly stiff, thicker layer. The Y8 is only MLS.


Comparison vs the Y8 MLS one. The Y8 gasket is backwards and it was really bright out, but you can see 2 holes between each cylinder are about 2x the size on the leaky gasket. But, the ports that circle cylinder 1 are wider on the Y8 gasket.


Better close up shot of the middle holes. Even though my Y8 gasket might not have been really "blown", I feel better knowing the right one is on now. And the cylinders were full of gross coolant/oil mix anyways.

vartok

personally i never liked the idea of re using head bolts on these concitering they are TTY bolts (torque to yield). when the HG blew in my z6 last year i ordered a set of ARPs... it changed it from head bolts to head studs which gives a much higher clamping force, and if you ever have to remove the head again, you dont have to worry about getting new ones or cleaning out the threads in the block.... just my $.02

Skryblz

Yea, reusing the head bolts might have been a bad call. At least after the crap this motor has been through.

I started it up and it idles fine and smooth. I let it sit there ~ 30 min, get up to temp and bleed the coolant of air. I go to drive it just around my apartment complex, and it starts bogging instantly. It clears up ~3000, but I am giving it more gas than it should just to get it up in that range.

One quick circle, park it in the same spot, but it's barely alive at this point; really rough low idle (550 maybe), thumping/loping sound out the exhaust. No smoke or distinct smells though. I turn it off and check the head bolt torque and they are all at 52 still. I tried upping the idle via the TB screw, but this only kept it from stalling out.

While it was sitting there you hear it clear up and the idle comes up to 8-900, but then it gets bogged again, shakes and the idle drops. It will do this on off every few minutes, bog a bit, clear up and smooth out, then bog and skake, etc...

I can't justify spending $140 on ARP's, another $50 for new OEM bolts though isn't too bad.

Should that HG I just put on be OK still or is it done for once fully compressed?

burnoutboy

iTrader: (22)

What exact steps are you taking to clean the head and block between gaskets?

tony_2018

micro fiber towel and some ebo grease.

TomCat39

Also after final torque how long did you let it sit before adding fluids and starting her up?

I've read a few times with MLS type gaskets that you let the car sit for at least 30 minutes before you add fluids and start it up.

Skryblz

To clean the block I used brake cleaner and a shop towel. Also my fingernails for stubborn spots. I then ran my finger tips around the block in figure 8's and all over to make sure there were no stuck on things or nicks/gouges.

After the final torque I waited overnight actually... only got to put the valve cover back on before it got too dark last night. I flushed it and put the fluids in this morning, with the dizzy and intake filter and started it up. Let it ran ~ 30 minutes before doing a circle around the parking lot.

Meh, I already ordered new OEM head bolts.

New question is, can I just take the old ones out and put new ones right in, or should I physically separate the head and gasket (I guess to fully let out any torque or compression on the gasket? Draining the fluids obviously to prevent seepage) before putting new bolts in.

NotARaCist

iTrader: (1)

You can remove and replace the bolts without removing the head. Just do them one by one, torquing to step 1 when re-installing each bolt. Once you have all bolts replaced, then torque to step 2 and 3.