[mrayner]

Car background:

• I have a 92 Coupe. 105k miles.
  
  
• Bought from reputable p-car company (Weissach) who addressed everything needed at 73k miles
  
  
• Car is my daily driver, no issues. Not a track car
  
  
• Generally well maintained, by mechanic. I only do minor stuff myself mostly due to time
  
  

Car issues I need to address:

Belts

• All belts were replaced when I acquired that car at 73k miles (7 yrs ago).
  
  
• Conclusion: It's time to get my timing belts done.
  
  

Engine reseal

• Oil consumption has steadily increased over last year. I have wet oil and carbon build up on spark plugs.
  
  
• Engine has never been rebuilt AFAIK
  
  
• My mechanic says this is due to oil leaking into the combustion chamber.
  
  
• Mechanic is recommending - front end reseal, lower balance shaft housing seal, rear main seal, new engine mounts
  
  
• Estimated as 12hrs labor + parts
  
  
• Conclusion: Yeah I think I need to do this. For now I add 1qrt of oil every week and change my plugs more often then I should
  
  

Cooling Systems

• I could start a separate thread on this one...
  
  
• I have been running hotter than I should, and have a slow leak in the cooling system.
  
  
• Through process of illumination I have concluded I have a leaking water pump that I need to replace
  
  
• Conclusion: I am on borrowed time and need to fix this one ASAP.
  
  

My goal here is to bring my car back up to spec to support my daily drive. Which is only ~10miles per day.

I love my car and am willing to invest (reasonably) to keep it running well.



The cooling system is most risky so I plan to get that sorted in the next week. But thinking everything else might be best done at the same time: belts, and engine.



So my question to the forum is:

• What do you think of my mechanics' recommendation on the engine?
  
  
• Assuming I get the engine work done, what other things should I do while in there (considering my goals of daily driver)
  
  

Thanks!

/Mike

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[tamathumper]

That is quite a bit of oil consumption, but I'd say that or your cooling system is not your biggest concern. The timing belt is way overdue and really should be done before you drive the car any more. Thankfully, you can do the (leaky) water pump at the same time. Old timing belts tend to snap when the car is being started, and you'll be out a lot of dough if that happens.

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[vliegwielolaf1234]

i do not see reseal job solving the oil burn isue , carbon build up on your plugs , it is leaking in thru either the valves (in that case you would need to take the head off and get it rebuild , or it is getting past the piston rings wich would be even more time consuming because the engine needs to come out .



leakdown test and compression test would give a better indication



But get your belts and waterpump done , i would not drive the car before that another mile .

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[Lear35A]

I have to wonder about the mechanic too. The things he wants to do are commendable, but none of them have anything to do with oil getting into combustion chamber.



To fix that it's time for a valve job and new head gasket. OTOH you can buy a lot of oil and spark plugs for the cost of that valve job. That's a decision that depends on your personal preferences and bank account.



That said, do the belts NOW. That's not optional.

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[DaveN]

FWIW my car came from Weissach as well in 93, small world :-) I would tend toward getting your head done. My mechanic sent mine over to Vancouver before I Supercharged it and it was only 500 for a refresh. I got the extra special 1000 dollar job because I was going to boost the engine. Scan auto knows 968s well if you need a second opinion. They are a bit pricey though.

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[Tom030]

"Through process of illumination I have concluded I have a leaking water pump that I need to replace"





Maybe not. There is a seal/O ring, #6 on the schematic, that is known to leak giving the impression of a bad pump. It's hard to see but easy to feel. Check under it for for a leak. If damp replace the seal, might save you a few bucks. I was told at 70K I needed a new pump. Replaced the gasket and put another 50 on it before replacing pump as a "while I'm in here" item.

~tom



   

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[Scott Collins]

Hey Mike,



My guess is that your water pump is just about gone based on miles and time. When you get in there and remove it,

you will be able to by hand turn the pulley that drives the impeller. When I did mine a couple of years ago at just under your mileage I found that it would hang up, not spin smoothly. I had a new pump on hand and compared it to that and it was obvious that the bearing in the old pump was just about shot.



IMHO your mechanic's list is a good one for your car's age/miles. If you do all of that, I suggest you add a couple of items that

are in the "while you're in there" category:



1. Main crank seal and new oil pump drive gear with new o-rings.

2. Oil filter housing gasket and seals - this will require removal of the heat shield and add a couple of hours to the bill. But it can be a source of fuel and oil mixing.

3. Replace transaxle fluid.

4. Replace both balance shaft races and front oil seals.

5. Check passenger side castor block for degradation of rubber from leaking power steering fluid and/or oil.



Note: have your mechanic check the vacuum lines and be careful around the air/oil separator. A vacuum line attaches to the top and believe me when I tell you that it can get brittle with age and crack the top or the air/oil separator. The part new is more than round trip airfare to Disney World.

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[blau]

Also if you're doing the rear main seal, it would be a good time to replace the clutch if your car is a 6-speed...since at that point it should only add less than an hour of labor to get the clutch out and new one in.

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[Scott Collins]

Blau - excellent suggestion to save time/money.



Mike - by the end of this thread, you will have replaced every part on the car! <img src="/forum/images/smilies/968/smile.png" class="smilie" alt="" />

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[DaveN]

Forgot the forum slogan 'Where the enthusiast's meet', time to change it to 'While you're in there' :-D

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[tamathumper]

Then add the throwout fork pivot pin and needle bearings,... <img src="/forum/images/smilies/968/wink.png" class="smilie" alt="" />

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[mrayner]

Thanks everyone for the advice! I am scheduling to get the belts done and cooling system fixed next week.



tamathumper - Oil consumption depends on my mileage. If I drive from Vancouver to Seattle (~150 miles each way) I need to add a quart each way. Typically I need to add a 2-3 quarts between each fill up. I know this is high, even for our cars.



Tom030 - Good point. I will check the seal ring first. I have no history indicating if the water pump has ever been replaced, so it is on the list to be replaced soon anyway.



Beau - Yes I have a 6 speed. Clutch was replaced 8k ago. I'm good on that front.



Scott - Great additional "while you're in there" suggestions. Appreciate it.



I just completed a compression test here are my numbers. This is from a warm engine, 8 cranks, all plugs out:



1 - 175

2 - 178

3 - 180

4 - 182



Coincidently #1 is the cylinder who's plugs build up oil deposits and eventually fail (after ~5k), Requiring me to change plugs more often.

I squirted some oil into #1 and it retested at 188.



I think a leak down test is in order.

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[mrayner]

I just realized I should have tested all 4 with oil to see how they compared. I'll do that.

Let me know what you think so far of the compression #s.

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[tamathumper]

Well, if you're losing that much oil you have two options. I'm guessing you have worn valve guides (but a little surprising at 105K) that will require a rebuilt head, or you could just change your license plate to say "VALDEZ". <img src="/forum/images/smilies/968/wink.png" class="smilie" alt="" /> I think RSBarn has an exchange program and different "stages" of head tuning.

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[mrayner]

Found the source of my coolant leak. See if you can guess? Turns out the water pump is fine. I did replace the thermostat, lower radiator hose and heater valve for good measure.

[sharedmedia=gallery:images:2407]

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[mrayner]

Timing and balance belts done, along with all three rollers and idler pulley.



I also had a leakdown test done. Horrible news: 95%, 25%, 8%, 8%.

Leak is from the cylinder/rings in #1 & #2.



Decision time.

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[Cloud9...68]

[quote name='mrayner' timestamp='1373157886' post='145301']

Timing and balance belts done, along with all three rollers and idler pulley.



I also had a leakdown test done. Horrible news: 95%, 25%, 8%, 8%.

Leak is from the cylinder/rings in #1 & #2.



Decision time.

[/quote]

Sorry to hear that, but I've always been curious - how can you differentiate between valves and rings in a leakdown test?

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[kwikt]

Listen for the air escaping when pressurized........if you here hissing air from the intake/throttle body area leads to Intake valve. Hissing from the oil fill cap points to rings. And hissing sound from exhaust is exhaust valve.

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[Cloud9...68]

[quote name='kwikt' timestamp='1373203847' post='145309']

Listen for the air escaping when pressurized........if you here hissing air from the intake/throttle body area leads to Intake valve. Hissing from the oil fill cap points to rings. And hissing sound from exhaust is exhaust valve.

[/quote]

Yes, I'd heard that that's how people do it, but it must take some practice to make a correct interpretation, For example, I would think hissing from the oil fill cap could be caused by either rings or valves, or possibly head gasket, for that matter. And hissing from throttle body or exhaust could be intake or exhaust valves, respectively, but it could also be head gasket as well. I've never tried it, but it seems like it could be challenging to interpret without a lot of practice.

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[paulzebo]

Right on Cloud9..68! Sometimes it hard to differentiate, but not when you have a cylinder at 95%. That should sound like a broken air line in the crankcase, TB or exhaust. TB needs to be held in the wide open throttle position during the test. Sounds somewhat suspicious also. I don't see where mrayner has any drivability issues with the engine or am I missing something? At 95% there should be a dead miss. You're leaking out 95% of what was put in. That 5% isn't enough to fire the cylinder. It's also not supported by the compression test of 175 dry/188 wet. 95% is just way high for an engine running otherwise ok. Any number above 30% on a leak down is bad news. If it is 95% I would suspect bad valve seating or broken rings. The tech says "Leak is from the cylinder/rings in #1 & #2", but broken rings won't give a this high of a static compression test of 175 dry/188 wet. These numbers are not making sense to me. I think a recheck is in order. Pressurize each cylinder and listen in the crankase for a loud hissing sound when comparing each cylinder. I suspect you will hear about the same amount of "hiss" coming from each cylinder(good thing). If you do, go for the head rebuild. The guides are probably bad and the valve seals are gone. Nothing a complete head refresh won't fix. If you hear a much louder hiss coming from #1 than #2,3,and 4, it's a bad day.



"If I drive from Vancouver to Seattle (~150 miles each way) I need to add a quart each way. Typically I need to add a 2-3 quarts between each fill up."



That's a lot of oil. Most manufactures say an acceptable limit for oil consumption is one quart in 2000 miles under normal service (no high rpm's). It's sounding like all the oil is being consumed by the engine when a large amount may just be leaked out. Which may be why the Technician concentrated on the reseal rather than a head rebuild. So, do you see blue smoke when you accelerate, when you first start the car or both?

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