97 Tercel: Valve seals changed, oil smell persists

Background

---------- This is a summary of the threads:

Re: Changed engine, heated ventilation smells oily

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Re: Ease of Leak-Down Test During
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was an oil leak, and original engine ran dry was replaced byused engine (not remanfactured). The sensors on the original enginewere scavenged and put on the replacement. There was a persistentchemical smell that caustic effect on eyes and throat over, punctuatedby burning smell (burning oil comes to mind). It did not matterwhether fan was on vent/recirculate, or hot/cold. Engine burned oilquickly (half a quart over serveral hundred km). Coolant remainedclear, and oil was not milky. There was black smoke during startup. During the first visit to troubleshoot, no signs of external oil leak was seen. Apparently, the exhaust was tested and found to be normal, but no details of how on the work summary. The air ducts were blown (I assume by shop air).

Worn valve seals were suspected. They were replaced on a 2nd visit, leak-down test didn't indicate any problems, pressure test of the coolant system did not reveal wet spots in the heating core (according to a tech, the core was not removed). Engine was "flushed" and a teradyne was performed.

Currently

--------- For the past week (since the valve seal replacement), the caustic chemical smell persists at noticable levels, and the burning smell is gone. Instead, there is a hot oil smell; I suspect that this is what the chemical smell turns into when the engine has warms up. A sure sign of prolonged exposure is continued coughing for upto a day after the exposure. The shop techs hardly notice the smell, if at all, though friends do; this is not surprising, considering the strong smells in the shop. Friends are only exposed to it for short durations, and only some are bothered by it.

Keeping all windows open while driving only reduces the problem; the hot oil smell is noticable outside the car, comes in through the windows. It is more noticable when travelling at low speeds (1st/2nd gear), and especially right after a duration of high revs e.g. shifting from 1st 2nd (maybe during a left turn), downshifting into

2nd, or just when the lights are against you during crowded city driving.

There doesn't seem to be any fresh fluid spots on the ground where I park. This observation is slightly complicated by the fact that there is melting snow, and large spot is due to the leak from the original engine.

Oil still seems to be burning at approximately the same rate as before. The symptoms don't match that of a head gasket problem. There is still white smoke during startup, while the smoke appears invisible after engine warms up. I'm not sure how to distinguish between water vapour and coolant in the exhaust.

In addition to a possible external oil leak onto a hot part of the exhaust system, JeB suggested that the crankcase vent might be dumping into the engine compartment. I was googling and asking people about this, and found that the high crankcase pressure that results from a plugged PCV valve can also cause oil to leak out from any seam. I was hoping that more experienced NG participants can answer some questions I have about this line of thinking.

  • Venting into the engine compartment, and associated oil leaks, would manifest during engine operation, especially high revs. Is this a good possible explanation for why the fumes seem more noticable at low speeds and right after high revs?
  • Wouldn't this cause outward signs of an oil leak e.g oil stains on the engine components? None were seen. Would the heat of the engine exterior cause them to evaporate?
  • How likely is a plugged PCV valve when I don't see the following symptoms?

- Rich fuel (black exhaust) due to lack of dilution by crankcase vapours

- Rough idling due to upset fuel/air mixture

  • A person I talked to said it wouldn't be too surprising that fumes get into the passenger compartment from the engine compartment even when the fan is set to recirculate, since the barrier is anything but a perfect seal. However, my mechanic mentioned that he checked all the seals between the engine compartment and any airway that might lead to the passenger compartment. To what degree is each person correct?
  • Though I still trust my mechanic, I'm considering bringing this to somewhere else to get a fresh perspective. I don't think I can continue using myself as a guineau pig in trying find clues about what conditions are linked with the fumes. Any opinions on this? Up til now, I can dress warmly and roll all windows down, but it will soon be raining/slushing/snowing, and I need to blow hot air against the windshield.

Thanks for any thoughts on these.

Tercel Owner

Reply to
Tercel Owner
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Have you considered the possibility of a mold in the vehicle? I have had several customers over the past years describe what to them is a "chemical smell" (their words) that irritates their eyes and throat, only to find the presence of mold in the HVAC system and once even growing under the carpet. Maybe you need to back away from the intense focus on the engine as a cause. Just a thought.

It can, and it most certainly will. Particularly around the VC gasket and front engine seals.

I would think that the regular occurance and intensity you are decribing would require a whole lot of fumes entering the passenger compartment from the engine compartment. Enough to cause other driveability issues with the vehicle, of which it sounds like you have none. But, for peice of mind pull off the VC and check to see that the PCV passageways are clear, the vent tube is not blocked, and the PCV valve is operating.

Reply to
Qslim

The fumes only enter the passenger compartment when the engine is running. So it can't be mold on the carpets. If it is mold, it would be in the air ducts. However, my impression is that they have spent a lot of effort cleaning them. The strongest indication against mold is that the problem did not exist prior to replacing the engine. However, it is a possibility.

Haven't been able to surf to a picture of a front engine seal -- might have missed it, as I've have avoided downloading "flash" content. I'm puzzled by the VC gasket. Wouldn't the excessive pressure be down in the crankcase? I would have thought a leak would show up between the engine block and the oil pan (I'm assuming they are separate pieces, with a gasket in between).

The techs don't notice the smell very much, but most all of my passengers have noticed the smell; about half of them complain about the effect of the fumes on them. That is over a relatively short duration. The fumes are light enough that I can pursuade myself that it is not of any consequence, aside from the alot of harumphing and occassional coughing. It is not until the end of the day when the cumulative effect is felt, especially if I do a workout. I notice that I'm out of breath throughout the night. On days which I don't drive, or drive very little, there less or no effect, aside from the after-effects of the previous day; these abate as the day wears on. When this happens for weeks, the correlation between driving and breathing becomes very noticable, despite its easy dismissability from considering any single trip. On days when I do a lot of errands with the car, the problem becomes much more noticable even with all windows down and the fan on cold/recirculate. If I'm driving mostly on the highway, it is not that bad. Subjectively, I think it is worse with the fan on ventilate.

You are right about lack of issues with drivability -- except for the serious loss of oil (half of the level between min & max in a matter of weeks, with nonexceptional amounts of driving i.e. not for any kind of transportation business or intercity driving). Other symptoms of plugged PCV are missing: no black exhaust once warmed up, no rough idling, and no problems with acceleration response.

I'll look at the PCV system tomorrow and try my hand at pulling it apart. Thanks for your thoughts on this.

Tercel Owner

Reply to
Tercel Owner

I didn't actually put my face down to sniff it, but maybe I should have. I did try to place the smell when the engine was warm and the exhaust was invisible. I thought I smelled gasoline, but only at moments. The inside of the exhaust pipe is sooty black. I wasn't sure how long one should stay sniffing the exhaust, so I stopped after about 20 seconds.

I find it tricky to assess whether a fume smells like coolant or not, based on sniffing the underside of the rad cap. The smell of liquid coolant is so strong that it's hard to match up with a light scent. I liken it to bleach; if I sniff at the spout of the bottle, the experience would be very different than walking into a laundry room in which bleach is being used.

Unfortunately, I haven't been tracking mileage. I'll take a sniff of the oil to see if a gasoline scent is present. About injector leaking gas into the combustion chamber, my view into the engine is still pretty conceptual. It's not clear to me what pathway is available for the gas to leak down to the comubustion chamber, aside from the proper way (through the valves). Wouldn't it have to leak into the crankcase to dilute the oil?

Since the exhaust is white when the car is cold, I suspect that the problem is not excess fuel leaked into the combustion chamber. But I will give a sniff. I should also start tracking mileage. I suspect it isn't as good as normal for a Tercel, since I keep windows down on the highway.

I'm surprised to hear your uncertainty about whether my car has PCV (97 Tercel). From googling around, my impression is that it is the rare and old car that doesn't have a closed PCV system. Is this right?

I'll look at taking out the PCV valve.

Thanks for your take on my questions.. Your sentiments re. Toyota dealer reflect my own. My mechanic deals mostly with Japanese cars, and much of it Toyota. So I am confident in his competence. However, a fresh point of view might help uncover somethings not currently suspected.

Tercel Owner

Reply to
Tercel Owner

Yeah, it would. And the crankcase is connected via the PCV passageways up through the block, through the head, and into the valve train area. Thats how oil gets into the oil pan when you pour it inside the valve cover.

Do you know what they used to clean them with?? If there are green growers in your vent system, blowing air through them will not do anything. BG makes a product called FrigiFresh that does an excellent job of killing anything in the HVAC system, although it is a bit pricey.

Reply to
Qslim

Sooty black suggests unburnt fuel from a too-rich mixture, poor spark, etc.

If you're not losing coolant, then I doubt if you'll smell coolant in the exhaust.

An injector leaking in the intake can dribble past a valve in the open position and into the combustion chamber. Depending on the shape of the top of the piston and how much fuel is leaking, the fuel will either pool on top of the piston or get on the cylinder walls, where it can seep past the rings and down in to the crankcase. This would have to be a pretty big leak to do this so you would probably have poor fuel mileage and a rough start-up.

I always keep track of fuel mileage because a drop in mileage can indicate problems with the car.

Almost all cars use a PCV valve in the PCV system but I seem to recall seeing or hering about an engine that did not use a conventional PCV valve in the system.

I'm impressed with your willingness to do your own research and study how cars work!

Reply to
Ray O

I'm glad somebody brought up the possibility of a mold. While I doubt any short term chemical exposure would cause you much symptoms after being away from the car, a mold might. I have a car right now that has a mold problem and it causes coughing and makes me dizzy within 5 seconds of being inside the car. Thanks for the FrigiFresh idea, never heard of it and it's just what I have been looking for.

As far as the PCV valve I kind of doubt this is a problem, but it is a very easy fix. If you have not replaced your PCV valve in sometime it wont hurt to do it, and will cost you about $3 and 5 minutes of your time.

Reply to
Josh

No rough start. Actually, been a busy few days, have yet to follow up on the smelling of oil for gasoline smell.

I actually don't have time (need to put more toward getting some Zzz's). But necessity is the mother of getting knowledgeable. The problem is not going away, and problem cannot be ignored.

I turned my apartment inside out to find that tercel manual I bought years ago. Carved out half an hour to study the PCV, and it seemed simple to check. My mechanic also said he checked it.

Thanks again for the suggestions and descriptions. Still have to follow up on some of them.

Tercel Owner

Reply to
Tercel Owner

Yes, it is strange (to someone who is just picking this up). In simple concept diagrams, the crankcase vapours simply go through a hose to a point at the intake manifold. In the Tercel manual, they travel up the engine block.

I can certainly follow this line of questioning when I bring it in on Monday (they're booked up this week). He has suggested it before. I would be puzzled as to why it so suddenly came about when the engine was replaced. And it doesn't explain the lost oil, though there might be separate, unrelated problems.

Tercel Owner

Reply to
Tercel Owner

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