[Chubby Bunny]

• Losing 1 - 2 qts per fill-up.
• No noticeable oil leaks on engine or underneath car
• No exh smoke
• Starts fine
• 1/4 spark plugs was oily when removed
• 175K miles on car
• Pretty thick layer of soot in tail pipe and exhaust is aftermarket
• Replaced PCV
• Compression seemed ok but maybe I'm doing it wrong.... it's been a while

o warmed up car
o disconnected distributor
o I cranked the engine about five revs for each cylinder.
o Readings were all 180 after five revs and I noticed that pressure continued to build beyond 5 revs

At this point, I'm open to any theories on where the oil is going, or what I've failed to check

 

[jwharnish]

• Losing 1 - 2 qts per fill-up.
• No noticeable oil leaks on engine or underneath car
• No exh smoke
• Starts fine
• 1/4 spark plugs was oily when removed
• 175K miles on car
• Pretty thick layer of soot in tail pipe and exhaust is aftermarket
• Replaced PCV
• Compression seemed ok but maybe I'm doing it wrong.... it's been a while

o warmed up car
o disconnected distributor
o I cranked the engine about five revs for each cylinder.
o Readings were all 180 after five revs and I noticed that pressure continued to build beyond 5 revs

At this point, I'm open to any theories on where the oil is going, or what I've failed to check

Arn't old cars fun?
1-2 qts/ fill up is quite a bit. 1 plug oily so some oil got to be burning at lease in that cylinder.
Did you check coolant level? If bad head gasket you could have oil getting into coolant. That would be clear if you check coolant.
If no oil leaking outside engine, then it's going inside engine and usually means ring job and or head gasket job, or oil seals on valves.
No cheap fix for this one.

 

[Dave_Darling]

Look at your coolant in the overflow bottle and in the radiator itself. (Obviously now when it's hot.) If you see a chocolate milkshake, you've got oil in your coolant.

When you check and/or fill your oil, do you see chocolate milk there? Water (possibly coolant) in the oil.

Neither of those is a good situation. There aren't that many ways that coolant and oil can mix, and the most common is probably a head gasket issue.

If you don't see any chocolate, then you're probably just burning oil, possibly with a small leak (or six) as well. Leaking oil will generally travel down and to the rear, so look at the bottom of the engine and see if there's any dampness. If so, that's a leak. Trace up and forward to see if you can find the source.

Burning oil will be due to valve guides/seals, or rings. Dealing with the valve guides is less invasive than rings, but both involve some pretty heavy-duty dismantling of the engine.

Good luck!

--DD

 

[Chubby Bunny]

DD - did you used to own a Porsche 914? There used to be a Dave Darling on the 914 website who was a frequent contributor. Coincidence?

 

[bambbrose]

I've never seen a car burning that much oil that it wasn't the rings. The compression can still be good with the oil control piston ring not being good. There are multiple rings on each piston. One quick test is to pull the oil cap off when it is hot and see if it puffs smoke out of the oil filler area. This is a sure sign of blowby.

 

[Dave_Darling]

There used to be a Dave Darling on the 914 website who was a frequent contributor. Coincidence?

Hiiii!!!! I still have the 914, though it hasn't run in a while.

--DD

 

[Chubby Bunny]

• Checked coolant. It was low so I couldn't see the consistency but it definitely smelled oily and not sickly sweet.
• Engine oil looked normal.
• After I warmed up the car, I opened the oil filler cap and a very fine cloud came out but also, there was considerable pressure coming out of the hole as if I had my hand over the tailpipe.... it smelled like exhaust. For a comparison, I tried this on my Chevy Metro and there was some pressure, but not nearly as much. But that's a 1.0 liter engine.

Somethings definitely not right and I think I'm in denial about the possibility of ring failure. I should probably take it to a mechanic to properly diagnose. Again, it starts and runs fine!

 

[AttackCRX]

Have you tried a cylinder leakage test? That'll tell you if it's top end or bottom and also where it's leaking from.

 

[Chubby Bunny]

I probably should do a leak down test; I have a test kit.

The mechanic is booked until late April so I will keep testing.

Today I put a paper towel over oil fill and it stayed in place on its own with the engine running, meaning that the crankcase is alternating between vacuum and pressure, which I believe means the pcv system is functioning properly. Also, if blow by was excessive, I assume the excessive pressure would have blown it off the valve cover.

I'd also like to find another comparable year civic to compare the amount of blow by.

Besides the usual suspects, I have a couple of other theories on what could be causing this, but they're not very good.

• It has 185/60/14 tires, which means 2 inches more circumference, so it's kind of like driving in too high of a gear. It's definitely noticeable. Perhaps this additional resistance on the engine produces more oil consumption.
• I don't know this, but suspect that the PO put in a lower-temp thermostat. Perhaps the pistons aren't fully expanding.

 

[bambbrose]

Its a long shot but you can try to Sea-foam the crankcase and also let it soak on the pistons. I'm not a fan of this on a healthy engine but I have seen this break up deposits and help piston rings settle on a motor that had been sitting for a long time. Just throwing out ideas. If the coolant isn't changing in volume the oil has to be going out the tailpipe. That means it is leaking into the cylinders from the rings or the head, there is no other explanation.

 

[jwharnish]

I probably should do a leak down test; I have a test kit.

The mechanic is booked until late April so I will keep testing.

Today I put a paper towel over oil fill and it stayed in place on its own with the engine running, meaning that the crankcase is alternating between vacuum and pressure, which I believe means the pcv system is functioning properly. Also, if blow by was excessive, I assume the excessive pressure would have blown it off the valve cover.

I'd also like to find another comparable year civic to compare the amount of blow by.

Besides the usual suspects, I have a couple of other theories on what could be causing this, but they're not very good.

• It has 185/60/14 tires, which means 2 inches more circumference, so it's kind of like driving in too high of a gear. It's definitely noticeable. Perhaps this additional resistance on the engine produces more oil consumption.
• I don't know this, but suspect that the PO put in a lower-temp thermostat. Perhaps the pistons aren't fully expanding.

Not a tire size issue, not a thermostat issue. Motor sealing issue.
Notice you said coolant level was low but smelled oily.
Bottom line on this is motor job. Even if you only plan to pull head for head gasket, you'll be replacing valve seals and probably do valve job. That's probably best case, but my guess is once you pull head you'll see ring failure and oil soaked piston. At this point rings, maybe new overbore piston to freshen bore on old motor, bearings, etc. Motor job.

 

[Chubby Bunny]

Bottom line on this is motor job.

I think the person who sold it to us knew that. We got it for an OK price.

I took a closer look at the antifreeze. Seems like there might be some contamination but not enough to explain the oil loss. Spark plugs all look a little different but none that are oil soaked.

I think I will re-check compression and do a leak-down test to see if I can isolate the problem. I'm hoping it's valve stem seals and not rings. If it's rings, I might try some snake oil as a last resort.

 

[bambbrose]

What is your goal for the car? Seems like you have a great excuse to swap in a better motor

 

[Chubby Bunny]

Great Question. It's my 16yo daughter's car. She bought it with her own money. So our goal is minimal investment.... mainly just addressing deferred maintenance issues, un-doing past modifications that went badly, like the ds power window. If I have to, I will spring for a replacement engine.

 

[Chubby Bunny]

So it took 200 miles for oil to drop from the high to low mark, which I think means 200 miles per quart.

 

[jwharnish]

Great Question. It's my 16yo daughter's car. She bought it with her own money. So our goal is minimal investment.... mainly just addressing deferred maintenance issues, un-doing past modifications that went badly, like the ds power window. If I have to, I will spring for a replacement engine.

You have a serious decision to make on the car. Motor needs attention and might as well consider to worst for that. rings,bearings,seals,head gasket, etc. so you have to know what a rebuild will run. Vs buying a replacement motor which may or may not be any good. You are talking about a 34 year old car. Not sure what rebuilds run, but if guessing I'd say 3K.
You have to way that against what the car will sell for to recoup your investment. 88 HF's are ideal for motor swap's. Drop a b16 or b18 in it and you end up with a great driver. Might be above the budget for you, but selling it before investing any more might limit your loss.
Good Luck.

 

[Chubby Bunny]

I appreciate the advice. I feel committed to keeping it at this point. If we sold it, I'd want to be up front about the oil consumption, which means less $$. She loves the car.

If this were an old Chevy, I'd just buy a rebuilt short block.

 

[bambbrose]

I would find a JDM sohc ZC engine or the D16A6 (both the same). It is drop in as you already have PGM-FI wiring, and the swap uses all OEM/original parts, and can usually be had for $200 to $600 as they are plentiful compared to the HF engine.

There are many guides online on how to do this swap and it is only a weekend job. Many D16A6 engines are out there, removed from Civic/CRX Si models in favor of bigger engines. It will actually add value to the car in the long run, still get amazing MPG, add more power so the car can get out of its own way, and keep things simple/reliable.

 

[jwharnish]

After reading about your motor situation, I reached out to a friend who is in the process of doing a b18 motor swap into his 88 hf. He already sold the hf motor, but then told me it was not an original HF motor. Previous owner swapped in another d15 motor and put all the hf stuff on it. Really thinking about this I would think any 88-91 d15 motor would work, and they are not a lot of money.
Plus there is also a guy in Kansas names Jeremiah Freeman who has a lot of CRX parts. At one point I remember that he stated he had maybe 30 CRX's. Maybe an HF? He's on Facebook if you do that thing.
ZC are fun thing to do, but this is for a 16 year old daughter first car project, so maybe later.
D16a6 motors are not that plentiful, as I have looking for one for quite a while.

 

[Chubby Bunny]

I'm starting to think more and more this is just a head gasket problem.

I checked the antifreeze again yesterday and could see oil in it. I also noticed that the level was low again. That's when I noticed a small leak at the bottom of the radiator. I wiped it off and when I checked again this morning, it was wet again but no puddles under the car. So perhaps oil is getting into coolant through the head gasket and then leaking out of the radiator. That would explain where the oil is going.