can oil be too rich??

[daweeen]

First of all, I don't work on my own car. I just need to know if I'm being taken for a ride. Here's the story an I'll try to make it short.....

70 ghia, 1600 engine, doghouse cooler (that's all I know of the engine, sorry, I'm a chick )

The mechanic that worked on my car retired. Ever since I've had my car (15 years) I've put 10W30 oil in it. About 2 months after my last oil change with my normal mechanic (the one that retired), I was in an accident (rear ended, but no apparent damage to the engine). Two weeks after that my oil light began flickering. I needed oil and added it then. The flickering continued, not a solid light, but a flicker. The flickering became worse, so I took it to a mechanic that was recommended to me. He stated that I should be using 20W50 oil, and that is probably the reason. I was in need of an oil change, so i had him do it with the 20W50. No flickering for a week, and then it started again. I brought it back and he placed a "oil booster kit" on it. now it's flickering even more. He said that if the kit didn't work, I would probably need an engine overhall.

Could the oil just be wrong for my engine? Could the accident have loosened some sort of wire which could cause the light to flicker? My engine seems to be running the same, no strange noises or smells. It seems to run slightly hotter than normal, but didn't know if that was the So. Cal heat affecting it..... Also, the light seems to not go on in the morning, but does on my way home from work? I don't know, is it posessed??

HELP!! Any help is truly appreciated....
Thanks!!
~joleen

[kubelkid66]

I didnt get hit...But i have The Same Problem...
I have no idea...My Engine Runs Great..But The Light Flickers..
sometimes it stays on for a little bit then goes off for the rest of the day..
Other times it flickers all day long.....

[vw carnut]

Check the wire running from the send unit to the guage for continuity.
may have a ground prob. ( could always do a quick ops guage hookup!)

[daweeen]

VW Carnut,

Thanks for the info. Is this something a novice could do and do I need special equiptment?

Sorry, I've always taken it somewhere, never worked on it myself...

thanks!!
~joleen

[Greg Rickard]

10W-30 should be an appropriate oil weight for LA. I live in the beach cities area of LA and use 10W-30 in my 71 Ghia, which has a 1600 rebuilt engine also. 20W-50 is a good choice for hot climates, like Phoenix, or older worn engines (not rebuilt).

I'd get a second mechanic's opinion, and don't tell him what the first mechanic said. I had a west L.A. mechanic try taking me for a major (rebuild) ride on my 1971 Porsche, so I know it can happen.

I don't want to speculate about if it is a loose wire, since I am not a mechanic, but it could be a bad oil sensor.

[roachghia70]

do you have a lot of miles on your engine?
if you do, it may in fact need a rebuild. the main difference between 10w30 and 20w50 is the thickness of the oil. 10w30 is a thinner oil so it would work great in a freshly built tight motor.
as a motor gets more miles on it, it begins to wear and the tolerances inside the motor become looser. when the motor loosens up, the pressure of the oil between these tolerances becomes lower. at that point, you can make up for the "looseness" by using a thicker oil. when the thicker oil stops helping, those tolerances have loosened up so much that a rebuild is the only thing that will help.
now, you said it is worse on the way home from work. this is because the oil is hotter on the way home. when the oil heats up, it becomes thinner. so in the morning, you will have the highest oil pressure, but once the engine is hot, the oil thins out and drops the pressure.
it sounds like you may need an engine rebuild, but by all means get a second opinion.
you should try a new oil pressure sensor because they are cheap compared to an engine rebuild, but the deciding factor is the mileage on the motor. if you estimate it to be over 100,000 then it is about time to rebuild.

[kpghia]

I concur with roachghia, my '74 was doing the same thing. It turned out I screwed up the timing and it was running too hot to begin with. First check the wire attached to the oil pressure sensor, then change the sensor itself. If it still does the same thing, I would change the oil pump before I overhauled the motor...only because I don't have lots of $$ or time to spend. I would then get a compression check of the cylinders since this is a good indication of the "looseness" of the engine. If compression is low, it's time to rebuild.

[daweeen]

I really appreciate all you help! I always know when I post a question here, I get really good advice.

The engine has not been rebuilt since I've had it (15 years) and for the last year, I drive about 80 miles a day. I'm trying to put off the rebuild, but know that it's going to be inevitable at some point... I just didn't want it now.. I'm going to check/change the oil pressure sensor, oil pump, and cylinder compression. Hopefully that will be it.

Thanks again for all you help!
~joleen

[roachghia70]

daween,
let us know how it turns out.


anyone else think it's weird that of the three avatars on the left, all of them are pictures of yellow ghias?

[Marc]

I run 20W-50 year-round in the `70 1600SP I have in my driver up here in Seattle. On a really cold morning in winter it's a bit much but I never put a heavy load on the engine until it's been running for about 5 minutes so it's not a problem for me. If it had a newer case I'd be using 10W-40, but like roachghia said when the internal tolerances get looser thicker oil is called for to compensate - in this "case", the lifter bores are a bit sloppy and even with all-new bearings and a good pump the oil light would flicker at hot-idle in the summer with 10W-30 or 10W-40. Oil pressure "booster" kits are completely worthless for this problem - they cannot affect hot-idle pressure at all, just the length of time that it takes for the oil to reach operating temperature. I do not recommend their use in a stock oiling system (in fact, there are very few instances where they do anything good - but so long as people keep buying them they'll stay on the shelves, which makes people think they're something that's needed, so they keep buying them.....).
Did the collision cause the lid to contact the generator pulley and tweak the fanhousing forward? It's possible for the cooler inside the shroud to be damaged from this, or the thermostat flaps could be binding, but if the generator never shifted that's probably not a concern.
The shock of the impact could cause the clamps between the heat pockets on the muffler and the heater boxes to dislodge; that'll not only reduce the amount of heat getting into the cab, it'll cause a loss of cooling air for the engine. If the muffler actually got smashed or the t'pipes pushed in there could be excess exhaust restriction (but you'd probably notice a loss of power/economy if it was bad enough to cause hot running). Is there still a good air-tight seal between the body and the engine all the way around? If not, hot air from below will be drawn into the fan and cause hot running.
These are all things that your mechanic should have checked, as well as the timing - like kpghia said that can cause hot running too; retarded timing and a bad engine compartment seal will definitely result in a flickering oil light at idle on a warm day since the late timing makes the muffler hotter than normal.
A thorough overhaul on a stock engine should be good for about 130,000 miles before everything inside is worn-out (many run longer than that provided they don't get run low on oil from the typical leaks that have developed by then, but it's a pretty good rule-of-thumb for scheduling a rebuild IMO). I recommend a valve job, and maybe new rings, at around 60,000 or so - past that point it's not at all uncommon for an exhaust valve to break. If you don't do this before about 80,000 it starts to become less and less cost-effective when you think about how many more miles are left before it'll be time to do everything, so the only rationale for it would be to increase the reliability for now... makes just as much sense to start saving $25 a week towards the overhaul and join AAA if you ask me. Even if she blows before you have $1500 saved up, hopefully you'll have enough socked away to swing a used engine and get it right back on the road.

[daweeen]

Thanks for the detailed info, Marc.

The only external damage is to the actual deck lid. The car went right over my tail pipes and into the back, no damage to the engine (the decklid was not pushed in far enough) and the bumper took most of the hit. There is not a tight seal around the engine, though. This was also my thought, because when I first added oil (the first flicker of the light) I had to pry the back open. When I closed it, it never sealed properly and the light has been flickering ever since.

The insurance paperwork has finally gone through and my car is in the shop getting fixed. I was wondering if not being sealed may be an issue, so I figured that I would get that fixed first, and then get a second opinion from another mechanic.

Luckily I have AAA Plus with towing up to 100 miles, and since I work 45 miles from home, I should be safe. Body work should be done next week, and I'll give you all an update. I appreciate all the input I received. You guys are always so good at helping out!!

Thanks, again!
~joleen

[daweeen]

Hi Guys,

Ok, the car's body has been fixed, the engine seal is very good and I still have a flickering light. I will go down the laundry list that you all provided and let you know what happens from there. The good thing is that I got a payout from the Insurance company for bodily injury, so that can go towards the new engine if needed!

Thanks again for your help!
~joleen

[Vw carnut]

Yeah,

Start w/the easy things such as OPS & work up to the $$$ items like the engine. Let us know whats up!