Been having a ton of seemingly related issues with my 97 ex coupe. The car typically runs fantastic in cold weather, but the more starts per day it would start to act weird. Issue enhanced ten fold on hot summer days. Car runs fine to work then struggles to start and extreme power loss on the way home. If I want to start it again right after I shut it off after a long drive, good luck. Have a slow coolant leak, gotta top it off every few weeks or it will overheat all at once. Got a radiator pump to find leak and it held pressure, no drippage whatsoever.

Well I just looked in my oil cap while topping off the oil. In the cap at the very top was tan/brown slime. Under the light you can see what looks like a hint of neon green... This has to be a bad head gasket, right? Don't mind replacing it, I bought this car with the intention of learning how to work on cars.

Other questions, how are the ebay head gasket replacement kits that come with some other components? From what I've hear they're pretty solid other than the valve seals. Will also be doing a valve adjustment while I'm in there.

What's strange is the coolant in the radiator seems to stay fairly clean, but the overflow reservoir looks very muddy, will probably replace. Should I do a coolant flush after head gasket change?

Car info: 1997 civic ex coupe with 221k, bought at 217k.

 

no. compression and leakdown tests. possible ignition related issue on the no hot starts. time for diagnostics.

 

so what would the slime be? It looked like coolant mixed with it. If I can find my dads compression test in the garage I will do it tomorrow. Am I doing this to test cylinder/ring wear or for a head gasket leak? I'm loosing coolant but there doesn't appear to be a leak.

 

I also gapped my spark plugs, they had a good color to them, and timed my engine last night. idle is also weird. it was really low so I adjusted it... it idles to where I adjusted it until I shut the car off and start it again after a decent length drive. If I rev it after that it will sometimes settle at the correct point then drop to 500-600

 

The symptoms you're describing do point to a head gasket breech as a strong likelihood. Losing coolant in the radiator while gaining coolant in the reservoir is a strong sign of a head gasket breech. What does the oil on the dipstick look like?...is it milky looking and/or discolored? Leakdown test would be the best way to check the engine's health and to rule out a head gasket breech. There are many symptoms and types of head gasket breeches: AGCO Automotive Repair Service - Baton Rouge, LA - Detailed Auto Topics - Symptoms of a Blown Head Gasket

The cheapest way to start is remove and clean the reservoir. Blow out the hose that connects from radiator neck to top of reservoir to make sure it's not blocked. Rent (free) a block tester at Autozone or O'Reilly's and buy a $10 bottle of Block Test fluid.A block test is not 100% definitive if the test is negative..however, if it's positive for emission gases in coolant then the head gasket is breached and will need to be replaced.

If you do a compression test do a dry and wet (teaspoon of oil) test. If the compression rises 10 psi or more when adding oil it points to worn compression rings.

 

It doesn't seem the coolant is going to the reservoir in an abnormal way. Do worn piston rings have any other negative affects that don't include burning oil and loss of power?

 

There is a green dye that can be added to oil to help see oil leaks. It lights up very bright green-yellow under a blacklight. It is likely the same thing that makes antifreeze green. Possibly the previous owner did that? Light brown frothy stuff will form on the oil cap if the car is used repeatedly for short trips.

Worn rings mostly mean smoke and high oil usage. They will also blow oil out the valve cover vent into the intake, which tends to foul everything up.

 

Your engine has two compression rings and one oil ring per cylinder. Can have loss of compression through broken or stuck compression rings without affecting oil usage and vice versa. Again, do a wet and dry compression test as shown on video below. Do the compression test with battery fully charged. You mentioned doing a valve adjustment soon and that may help it run smoother. Valves tighten, not loosen with daily driving, so there could be some valves that are out of spec and affecting performance.

In your initial post you stated:
1) Loosing coolant through possible leak but, no leaks found during coolant system pressure test
2) Have to top up coolant every few weels or it will overheat

If it's losing coolant without an external leak it's leaking internally via a headgasket breech, cylinder head crack, or crack in block (not likely). Internal leaks will f leak into ne or more of the cylinders and combusted in the cylinder that may or may not show up as white, sweet smelling smoke from tail pipe.
One typical spot of for an external leak you may have missed is the heater hose that connects to the cylinder head underneath the distributor. The distributor's o-ring is common place of an oil leak and oil leaking on to a rubber hose can degrade it prematurely and can cause slits or tears in that heater hose that may only show up when the engine is hot and under pressure. If it's a small leak through a slit in the rubber hose it may dry up before it hits the ground and drips will not be seen. Have you tried running the engine with a large piece of carboard under the engine bay that will show drip stains (oil, coolant, etc,,)?

eghatch9295 gave a good suggestion to do a compression test and leakdown test on it. A leakdown test is one the best diagnostic test for a combustion engine. Both shown in video below. He also said possible ignition related issue for poor starts after engine use. Remove distributor cap and inspect for corrosion or oil on the igniter and coil (ICM). Test both the igniter and coil: http://easyautodiagnostics.com/honda...system-tests-1

 

failed head gaskets are usually easy to diagnose with a compression test. block tests are very good, too.

 

I've never seen smoke from my car, closest thing is the steam(or is it smoke?) for the first 5 minutes of driving in cold weather. I rarely take my car for short trips, it's almost always my 15 mile trip to work and back 5 days a week. I'll have my dad follow me while I rev it pretty high to look for hints of smoke. Will do wet and dry compression test, along with leak down test and likely block test. Debating if I should invest in my own kits or to rent. Really want to figure this out, actually looking forward to doing head gasket swap to learn how but need to figure out for sure if that's the cause. I'll let you guys know. The obd2 scanner I have doesn't show live data, I have one on the way for that so I can see if it's running rich/lean and get an idea of how my cat is doing. I read about someone having a same issue from a messed up cat, he never mentioned what it was that screwed it up though.

 

That's a good idea. use a phone to communictae with your dad during driving so he knows when you'll accelerate/decelerate. Best to accelerate quickly, rev high in first gear and then decelerate quickly. If there is an internal leak seaping into a cylinder(s) it generally shows up through exhaust/tail-pipe on cold starts after the engine cools overnight. Also, if coolant is getting into cylinder(s) a lumpy idle may be evident at cold start for the first few minutes until operating temp. Problem is with older Honda's it's tough to tell because they are designed (through IACV) to idle at higher rpms until the engine is warm. As I stated previously white smoke may not show at all even though coolant may be getting into cylinders.

I had an E46 BMW with a cracked cylinder head and it idle lumpy at cold start until operating temp due to a crack in the cylinder head. Once the engine was at operating temp the heat/pressure sealed the crack and it idled fine afterwards. Only symptoms were lumpy idle at cold start and loss of coolant without an external leak. Engine passed a block test at cold start and at operating temp. I would never buy another BMW with over 50k miles on it..beautiful cars but **** proprietary engineering IMO. Honda's fall apart too in some ways but, design is simplistic yet intelligent.

Compression test alone isn't 100% definitive for a head gasket breech. If two adjacent cylinders have low compression readings then yes, there is most likely a tear in the head gasket between those two cylinders. Otherwise, if there is only one or none of the cylinders with low compression then a compression test doesn't rule out or confirm a head gasket breech. If there's one cylinder low on compression that's where the wet test comes in...if compression jumps up significantly after adding a teaspoon or two of oil then it shows the compression ring(s) are the issue and then you have to consider a re-ring or replace engine. If , during the wet test compression doesn't rise then the compression loss is through the cylinder head: leaking intake and/or exhaust valves, worn valve springs. So, knowing that info ahead of time either by itself or in conjunction with a head gasket breach allows you to decide to rebuild or replace engine. A leak-down test will give all that info at once and help isolate where compression loss is happening and to what extent.

OEM is always the best way to go IMO. Check sites like HondaPartsNow, Honda Parts Cheap. In the video below the guy gives great tips for HG replacement. He also has several other informative videos and explains in detail well.:

 

On mobile, don't see how to reply without quote...

Anyway, oem gasket + eBay gasket kit on the way. Hope they come before Friday so I can have all weekend to do this. Will still have to drive to work all week... Have my oil and coolant levels maxed out. Also ordered feeler gauges and straight edge so I can check for warpage and adjust valves. Oh and new bolts of course.

I warmed up the engine, 68 degrees outside, my friend followed me while I redlined. He saw grey smoke from the tail pipe, claimed it didn't seem blue.

As long as I take it easy I shouldn't do too much damage driving to work, right?

 

Download a 96-00 Civic service manual (free pdf online) and follow it for headgaket replacement. You'll need a torque wrench if you don't have one already. Torque pattern for headbolts also shown in manual and videos.

Refer to reply #4 (mk378) in this thread: https://honda-tech.com/forums/honda-...civic-3302203/
If you don't have any other option and have to drive it ... in the meantime roll windows down and set climate control to max heat and fan on...this will help prevent overheating.

 

Motor stays nice and cool until coolant is low. I keep on eye on my temp religiously. It's hot outside and ac doesn't work so I'll die if I turn the heat on. I'll get the service manual and look up guides, too. Thanks.

 

What is this white milky stuff under my oil cap?

have you done any diagnostic work, or are you just throwing parts at the car? let's say there is a leak, what if it's a cracked head? diagnose, then fix.

 

I should have done more diagnostics for sure but the parts weren't too expensive so I'm just going to do it. Only thing that hasn't arrived are head bolts. Definitely feels like head gasket cracked and expands under heat allowing coolant into head. I'll know after I do all the new gaskets, I guess.

 

best of luck, post up with results

 

You're on the right track.
Did you do a dry and wet compression test? if so, what were results?
Bring the cylinder head to a machinist to inspect for cracks, warping, valve leaks, worn valve springs. If it's been overheating you can expect warping more than .004" and more than likely will need to be milled flat. Also, it's a good time to install valve stem seals (inexpensive part) and preferably have a valve lapping performed...however, this may not be needed it passes a valve leak test shown in video below.

When I did a head replacement on my old '98 Civic EX it had a warped head and one head-bolt hole in the block was stripped. I used a 10mm helicoil kit and the depth of the block hole was able to accommodate 1 and 3/4 coils stacked on top of each other. I also added Loctite red thread locker on the exterior of the coils to keep them in place. Hopefully, that won't be the situation with your cylinder head.

Set your engine with first cylinder at TDC and make sure timing marks are alighned before head gasket removal. After setting at TDC/timing alignment either loosen and remove timing belt per service manual or remove as shown in another video by the guy's (old school funk) video below :

Valve leak test:


Valve lapping:

Valve leak test and alternative lapping method (not recommended for novice)

 

I'll do all of those tests tomorrow, thank you! I'm going to call a close machine shop to see how much it would be to inspect the head but I'm not made of money, any idea what that could potentially cost me? If it's out of my range and all these basic tests go well then I'll just re-assemble.

 

Rough estimate:
Inspection/estimate: free
Milling to flat: $40
Hot tank cleaning:$20-30
Valve lapp + polish: $150-$200
Stem seals you can buy for $20-$25..machinist may charge to install but would be much.

Not wanting to sound like a dick but, you're engine doesn't care if you're made of money or it not...it just needs proper maintenance and repair to run correctly. You can do it all yourself if you want to go that route. Old School Funk has videos on how-to. I brought my car's cylinder head to a machinist 30k miles ago. He did all of the above mentioned for $275 and I have no regrets.

 

$275 for all that is not bad at all, in my noob opinion. I have new seals. How important is valve lapp/polish?

Anyway, I have the head off. Milky tan sludge all in the valve cover, oil on head assembly looked mostly normal... weird. Coolant in radiator smells like gas, it's cloudy but not super cloudy. I'll resume cleaning and testing head tomorrow.

 

If the hg is compromised should I be able to see the problem? It looks fine to me, maybe an inner layer is cracked or part of it is compressed?

 

I didn't get my head very clean yet, going to the store to get better materials for removing the stubborn stuff tonight. I wasn't able to fit the .051mm gauge under the straight edge on the block but .038mm slipped right through. Anyone know the tolerances for the d16y8? Couldn't seem to find them. Thoroughly cleaning and checking block tonight, if it's flat I found a good machine shop to take the head to.

Edit: Fixed measurements.

Double Edit: Block is in spec, head needs to be shaved. Taking to machine shop to have it re-decked and valves lapped tomorrow morning.

 

soak the head in diesel if its that bad. let it sit overnight, spray clean.

 

Got scotch bright pads and got it clean enough. Like I said block is flat enough, head is going to machinist tomorrow. Valves didn't pass the water test, aren't seating well so I'll have him take care of that too then I'm throwing it all back together. Picking up a haynes tomorrow so I don't mess it up during re-assembly. Accidentally washed my marks off the cam sprocket so wish me luck haha next time I'll use white out instead of a chalk paint pen...