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Engine Specific Info and Questions => IDI Engine => Topic started by: VW on December 27, 2007, 03:17:30 pm
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I realize this is a dumb question but when driving my 85 Jetta the oil buzzer and light comes on after about 5-10 minutes.
I have checked the oil level and it is right where it is suppose to be.
I do notice it puts out black smokes but I thought this was due to too much fuel as the guy I bought the car from messed with the injector pump.
I also use Mobile 1 full synthetic and it still puts out black smoke.
If I let the engine idle it is fine.
It only buzzes and lights the dash light when driving.
I am thinking maybe it is the Turbo but wouldn't it smoke at idle as well?
This is my first IDI. I just want to make sure it is not the oil pump because if it is I want to replace it before I toast the engine or the head.
If it is the Turbo, can I replace the K24 with a K26?
Thanks in advance
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Do you have an oil pressure gauge? I have found these to be absolutely essential on any diesel VW.
Thats about the only advice I can give, though.
Could be a faulty sensor, but somehow I doubt that. Do you have a boost gauge to keep an eye on boost levels? And if you're blowing black smoke, you may want to turn back the fuel screw on your injection pump. It sucks, I know, but sadly black smoke means overfueling and that causes problems with engine internals and turbos because of increased heat. Thats where an exhaust gas temperature gauge comes into play.
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I'll get and oil pressure gauge. Where would I take my oil pressure reading from? The Head, Block???
Also I'll get a Boost gauge and an EGT too.
Thanks
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I'll get and oil pressure gauge. Where would I take my oil pressure reading from? The Head, Block???
Also I'll get a Boost gauge and an EGT too.
Thanks
You will see a wire going to a plug on the right hand side of the head or block. I forget which it is. I think its the head. Someone correct me. Anyways, I took that out and installed the gauge sensor there. This is for your oil light I do believe. So now you will only have a pressure gauge to monitor your oil situation.
There might be somewhere else to attach it, but this seems to be the easiest way.
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I realize this is a dumb question but when driving my 85 Jetta the oil buzzer and light comes on after about 5-10 minutes.
could be from too high oil temps. really hot oil tends to 'thin' out a bit giving low oil pressure
I have checked the oil level and it is right where it is suppose to be.
always a good idea :)
I do notice it puts out black smokes but I thought this was due to too much fuel as the guy I bought the car from messed with the injector pump.
most likely. you can adjust the fueling with the fuel screw. its a good idea to do it while the engine is running, but crack the locknut before its running (otherwise you could spark from the solenoid or something)
I also use Mobile 1 full synthetic and it still puts out black smoke.
no oil on this planet will get rid of black smoke :lol: only way to do that is with more air (higher boost if you're running a turbo, and intercooling helps) now synthetic oils do help suspend the black soot in the oil better than conventional which reduces wear and tear on the motor.
If I let the engine idle it is fine.
hmmmm..
It only buzzes and lights the dash light when driving.
i almost think that one of your dynamic oil pressure units is bad... i've had that happen to me before. but turns out the engine was actually dumping gasoline into the cylinder walls though... the oil was sooo thinned out!!! stupid gassers. so the oil was so thin that it was setting off the buzzer.
I am thinking maybe it is the Turbo but wouldn't it smoke at idle as well?
This is my first IDI. I just want to make sure it is not the oil pump because if it is I want to replace it before I toast the engine or the head.
yea good call. would be a shame to waste an otherwise good working motor. i would say to get an oil pressure gauge in there first though. just to rule out the electronic senders. they do go bad...
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Actually pretty rare for the oil pump to wear out so bad that you have low pressure....
Your Jetta listens to two different sensors: a low pressure sensor on the drivers side of the head when the engine is below 2000 RPM, and a high pressure sensor at the oil filter flange when the engine is above 2000 RPM. The reason being... what's acceptable pressure at idle might not be good enough on the highway !!
The low pressure sensor flashes the oil light, and the high pressure sensor flashes the light *and* sounds the buzzer... again, to get your attention on the highway.
What's happening is that your engine oil is heating up as you drive... and 5-10 minutes down the road it's hot enough (and therefore thin enough) that the oil pressure has dropped enough to trip the high pressure (above 2000 RPM) sensor. We know it's the high pressure sensor because of the buzzer.... and because the issue goes away at idle.
The previous advice (get an oil pressure gauge) is correct imho.. sometimes the sensors misbehave, but usually, sadly, the engine's bearings have worn enough that the pressure has dropped below critical.. again when when engine is hot is where it first shows up.
Some people have reported buying some time by:
(a) ensuring they have a proper OEM filter: Mann, Bosch, etc. If your filter is orange and has a four-letter word on it starting with "F" run, don't walk, to the store and get an OEM filter. ;-)
(b) switching to a thicker oil. You don't mention which Mobil you're using.. but if it's 0W30, 5W30 etc you can try a thicker range oil... Castrol Syntec is 5W50 for instance, and there are lots of 15W50 diesel oils out there if your climate is not too demanding.
Generally, in the end, your oil pressure gauge is going to tell you what's really happening and you can go from there.
If it really is low you can pull the oil pan and measure the crank and rod bearings... and replace 'em if they are worn. You will also be able to inspect the oil pump filler screen for clogs, and measure the pump for wear.
The other big culprit is the intermediate shaft bearings... often overlooked during a rebuilt (any idea when/if your 85 was done ??) and they tend to flake off and drain pressure like crazy.
When you get your gauge let us know what you find... at the oil filter flange.. when the engine is nice and hot.... at 2000 RPM. Should be at least 2 bar.
Vince
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OK, I will go get a Guage and hook it up at the head. I will report back with my results. Where exactly is the intermediate shaft? I use the 15W/30w by the way. I really appreciate the help. This site is the best!!
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you mentioned Mobil I...
so... I suspect it is 'thinning' with heat as described above.
I use 15w40 Amsoil HD diesel oil in my TD's and TDI's
for the beater (mechanicals) they get 4 qt 15-40 dino oil + one qt of 15- 40 Synthetic
I will warn you that my OP gauges on the head of HYD engines have been very worrisome for indicating low oil pressure. (~10 - 15 PSI at heat and road speed). Even my brand spanking new 1.9's only register 15psi at head. (unless cold). I will put a sensor at the filter housing and one at the head with a switch on my HYD engines. They have a higher volume pump, and less pressure. My Mech engines are often 50 PSI+ at the head. I have torn down a 1.6TD HYD because of the buzzer and synthetic oil combo... but the engine was fine. :oops:
The intermediate shaft is the first passage from pump, and if bearings are worn, pressures will be low at head. The synthetic oil is very nice to keep in the engine if it doesn't burn or leak. It will save your bacon on an 'overheat'. Lubricity is king, and cold crank nice too.
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Sorry it has been awhile since I have updated this but I parked the car until now to make sure it won't get worse until I had the chance to install the pressure gauge.
So I had installed it today and here is what I have to report.
Cold (just started up) the pressure was almost 40 at the head at idle.
3-4 minutes later the pressure was down to 20 at idle.
10 minutes later it was down to 1-2 at idle.
Now if I am driving down the road in 5th the pressure is about 20.
What does this mean? Is my Oil Pump hosed??
Thanks
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I agree with the chorus , Intermediate Shaft bearings. You might buy some time with a new oil pump but with readings like 1-2 psi I doubt it will help much. Sorry Dan
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Thank you,
So where is the intermediate shaft? Can I inspect the intermediate shaft somehow or prove it is the reason of low oil pressure? If so, can I easily change the intermediate shaft bearings??
I have never had one of these diesels apart before so I really have no idea what they look like inside or what makes up the internals.
Thanks, Jason
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The IM shaft is parallel to the crankshaft but above and to the front of the engine. It is driven by the back side of the timing belt and has a large flat faced drive pully in between the crankshaft and the injection pump. There is one bearing at the front of the engine and one at the rear near the bottom of the vacuum pump. The IM shaft drives a bevel gear which drives the oil pump and the vacuum pump. Some mechanics have found a way to replace the bearings without removing the engine from the car, but most will say that you have to pull the engine to do the job properly. Anyone else can jump in here with more detail. Cheers Dan
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OK, so if I pulled the motor to do this or if it could be done in the car, how tough is it to replace these bearings? Is this something a professional should do or could anyone tackle this?
Thanks
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Wow!! Those are both slick!! So is it recommended to remove the engine or??
I assume, I will need to remove the Vac Pump and all timing belt, Alt Belt etc etc..
What about the oil pan? And can I order new IM shaft bearings from a regular auto parts store or should I order those from the dealer?? or is there a recommended website?? Is it possible I will need larger than stock bearing??
Any good detailed write-ups on this procedure??
Thanks
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If I changed the oil pump for a new one could that help or is it a moot point? I figure if I crack open the pan to inspect the pick up screen I could easily change the oil pump at the same time? Maybe even install a High Volume Pump if there exists such a thing? What about maybe a thinker oil? I use 15w-30w now.
Thanks
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OK, well I want to try replacing the pump first as it won't hurt to have a new pump (especially a High Volume one) and since I have to open the pan to inspect the pick up screen I might as well change it. Can you recommend where I can order a 36mm Pump? It will be several months before I can tear down the engine long enough to swap out the bearings so for now I will hope to buy some time.
I really want to save my money for 1.9L IDI rather than invest to much in my 1.6L.if I can and just need to get my 1.6 to last until the end of summer or maybe just before winter.
Thanks
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I use 15w-30w now.
Thanks
Before changing pumps and everything, i'd change that oil, and use a proper filter, as others have already recommended doing.
15w40 or mabye a 15w50.
My old gassers would set the light and buzzer off when i used 10w30, changed to 10w40 and never came on again.
Cheap and simply solution.
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After 10-15 minutes he's at 1-2psi at idle.
Andrew
ahh i missed that part.
If thats the case it may just be the cheap temporary bandaid fix he is looking for.
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I will try the 15w-50w and a Mann filter first. I do a lot of driving. I will probably put another 5000-10000 miles on the engine before I pull it so I hope it can last that long.
I like this site a lot, you guys really are very helpful and not condescending like some other sites. You all deserve some serious pats on the backs:)
Thanks everyone.
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Sorry it has been awhile since I have updated this but I parked the car until now to make sure it won't get worse until I had the chance to install the pressure gauge.
So I had installed it today and here is what I have to report.
Cold (just started up) the pressure was almost 40 at the head at idle.
3-4 minutes later the pressure was down to 20 at idle.
10 minutes later it was down to 1-2 at idle.
Now if I am driving down the road in 5th the pressure is about 20.
What does this mean? Is my Oil Pump hosed??
Thanks
hmmm so you only tested at the head? any testing done at the flange? the flange should read a different (higher) pressure. try that :)
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What flange? I will check it as well and report my findings.
Thanks
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oil filter flange. take off the oil pressure sender and install your gauge there. oil pressure should be quite a bit higher there.
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The flange is where you can measure for the one official oil pressure spec VW give:
2 bar (29psi), at 2000 RPM, with the engine at normal operating temperature (rad fan has cycled once).
Having said that, 1-2 psi at the head is pretty darn low, regardless of what you read at the flange.